Smaller changes to the core vimrcs

Default to Ag (instead of Ack)... Much faster.
Performance improvements due to smaller history.
Don't remember the position in file (this slows Vim down considerably.

vimrcs/plugins_config.vim

@@ -116,3 +116,13 @@ nnoremap <silent> <leader>z :Goyo<cr>
 " => Syntastic (syntax checker)
 """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 let g:syntastic_python_checkers=['pyflakes']
+let g:syntastic_javascript_checkers = ['jshint']
+
+" Custom CoffeeScript SyntasticCheck
+func! SyntasticCheckCoffeescript()
+    let l:filename = substitute(expand("%:p"), '\(\w\+\)\.coffee', '.coffee.\1.js', '')
+    execute "e " . l:filename
+    execute "SyntasticCheck"
+    execute "Errors"
+endfunc
+nnoremap <silent> <leader>l :call SyntasticCheckCoffeescript()<cr>