.vimrc: add local libdirs for syntastic perl checks
better exec_filter - just use <> operator

I still love you, Perl.
(g)vim: Tomorrow-Night-Bright colorscheme, some keybindings

- F5 now calls :wall
- <leader>r to pipe through exec_filter (this probably not a long-term
  thing, but good for a current writing project)
- notes.txt instead of notes