misc: updates the vim syntastic config with correct style

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
misc: adds the option to specify the main nit module to syntastic

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
Merge remote-tracking branch 'alexis/vim-syntastic' into killnitc