vimrc: refactorized, showing trailing whitespace

* vim-airline, vim-gitgutter, vim-NERDTree,
 vim-fugitive plugins have been added
 system-wide, so removed from the config
* trailing whitespace is from now on
 shown and nicely highlighted using "•"
* when empty vim is open, NERDTree is shown

vimrc

@@ -27,32 +27,39 @@ endif
 
 call plug#begin()
 Plug 'drewtempelmeyer/palenight.vim'
-Plug 'https://github.com/suan/vim-instant-markdown', {'for': 'markdown'}
+Plug 'https://github.com/suan/vim-instant-markdown', { 'for': 'markdown' }
+Plug 'lervag/vimtex', { 'for': 'tex' }
+Plug 'xuhdev/vim-latex-live-preview', { 'for': 'tex' }
 Plug 'https://tpope.io/vim/surround.git'
 Plug 'https://github.com/tpope/vim-repeat.git'
-Plug 'https://github.com/tpope/vim-fugitive.git'
+"Plug 'https://github.com/tpope/vim-fugitive.git'
-Plug 'airblade/vim-gitgutter'
-Plug 'rhysd/open-pdf.vim'
 "Plug 'voldikss/vim-mma'
 Plug 'roxma/nvim-yarp'
 Plug 'roxma/vim-hug-neovim-rpc'
 Plug 'Shougo/deoplete.nvim', { 'do': ':UpdateRemotePlugins' }
 call plug#end()
 
+let g:airline_powerline_fonts = 1
+let g:Powerline_symbols = "fancy" " sth like this probably set as a default but won't hurt here
+let g:airline_highlighting_cache = 1
+
+let g:NERDTreeDirArrowExpandable = '▸'
+let g:NERDTreeDirArrowCollapsible = '▾'
+
 let g:gitgutter_terminal_reports_focus=0
 "let g:gitgutter_async = 0
-
+let g:gitgutter_sign_allow_clobber=0
-let g:pdf_convert_on_edit = 1
-let g:pdf_convert_on_read = 1
 
 let g:deoplete#enable_at_startup = 1
 
+let g:livepreview_cursorhold_recompile = 0
+
 " vim-instant-markdown options
-let g:instant_markdown_allow_unsafe_content = 1
+""let g:instant_markdown_allow_unsafe_content = 1
-let g:instant_markdown_mathjax = 1
+""let g:instant_markdown_mathjax = 1
-let g:instant_markdown_browser = "chromium-browser --incognito"
+""let g:instant_markdown_browser = "chromium-browser --incognito"
-let g:instant_markdown_autoscroll = 1
+""let g:instant_markdown_autoscroll = 1
-let g:instant_markdown_autostart = 1
+""let g:instant_markdown_autostart = 1
 
 
 " change cursor shape for different editing modes, neovim does this by default
@@ -72,8 +79,16 @@ command! W execute 'silent w !sudo tee % >/dev/null' | edit!
 
 " open a terminal in $PWD
 nnoremap <silent> <Leader>tt :terminal<CR>
+" toggle showing whitespace
+noremap <F5> :set list!<CR>
+
+vmap gb :<C-U>!git blame % -L<C-R>=line("'<") <CR>,<C-R>=line("'>") <CR><CR>
+nmap gb :!git blame %<CR>
 
 " ------ autocmd ------
+" automatically open NERDTree if vim is open on it's own (argc() ==0 )
+autocmd StdinReadPre * let s:std_in=1
+autocmd VimEnter * if argc() == 0 && !exists("s:std_in") | NERDTree | endif
 
 " Reload changes if file changed outside of vim requires autoread
 augroup load_changed_file
@@ -124,8 +139,8 @@ augroup vimrc
 augroup END
 
 """ autosave and load views
-""au BufWinLeave ?* mkview
+au BufWinLeave ?* mkview
-""au BufWinEnter ?* silent loadview
+au BufWinEnter ?* silent loadview
 
 au FileType xml setlocal shiftwidth=2 tabstop=2
 
@@ -151,6 +166,8 @@ nnoremap <silent> <Leader>ss
     \  call setpos('.', b:_p) <Bar>
     \  unlet b:_p <CR>
 
+match Todo /\s\+$/
+
 
 set softtabstop=4
 set tabstop=4
@@ -172,17 +189,16 @@ filetype indent plugin off
 set autoindent
 set backspace=2
 
-set nolist                    " show/hide tabs and EOL chars (hidden characters)
+set listchars=trail:•
-"set number                    " show/hide line numbers (nu/nonu)
+set list                      " show/hide tabs and EOL chars (hidden characters)
-"set relativenumber             " use relative number
+set confirm                   " ask confirmation like save before quit.
-set confirm                    " ask confirmation like save before quit.
+set wildmenu                  " Tab completion menu when using command mode
-set wildmenu                   " Tab completion menu when using command mode
 set scrolloff=5               " scroll offset, min lines above/below cursor
 "set scrolljump=5             " jump 5 lines when running out of the screen - NO
 set sidescroll=10             " minimum columns to scroll horizontally
 set showcmd                   " show command status
 set showmatch                 " flashes matching parenthese when cursor over the other one
-set showmode                  " show editing mode in status (-- INSERT --)
+set noshowmode                " show editing mode in status (-- INSERT --)
 set ruler                     " show cursor position
 set errorbells                " bells in terminal
 set undolevels=1000           " number of undos stored
@@ -194,14 +210,11 @@ set nofoldenable
 set encoding=utf-8            " important for powerline besides others
 set smartcase                 " override 'ignorecase' when pattern has upper case characters
 set noscrollbind
+set updatetime=1000
 
-
+syntax enable
-vmap gb :<C-U>!git blame % -L<C-R>=line("'<") <CR>,<C-R>=line("'>") <CR><CR>
-nmap gb :!git blame %<CR>
-
 colo palenight               " new fav highlighting
-set mouse=a                  " enable mouse in n,v,i,c,h modes 
+set mouse=a                  " enable mouse in n,v,i,c,h modes
 
 set laststatus=2             " show powerline status bar
 set t_Co=256
-let g:Powerline_symbols = "fancy" " sth like this probably set as a default but won't hurt here