Support setting options

[jkhoeini]

Support communicating with vim-mode (and probably the editor itself) by setting and getting (:set) options like 'hls', 'ts', 'ff', etc.

It probably doesn't make sense to implement a huge portion of options. However, options are a very important aspect of vim and they are just integrated into workflow of some of us. For example, if I want to temporarily turn of line numberings I just do :set nonu and when highlighting search matches gets in my way I do :set nohls and I can continue to my work without loosing the n command to go to the next match.

Also recently I needed to modify what motion commands like w recognize as word boundaries in Clojure files. In vim that is as easy as setting 'iskeyword' option in an autocmd. But in atom I don't know if that is possible at all.

[lloeki]

Good point. :set nolist is one I use quite often. I understant the use of :set nohls since I myself do :noh on a case by case basis for a similar use case.

[lloeki]

If applicable, setting vim options may depend on #2.

[mingelz]

I use vim-mode-plus now, it can highlight all matched searching words, and t9md has supported :noh at his ex-mode repo: https://github.com/t9md/atom-vim-mode-plus-ex-mode. Now, t9md suggest us to use this ex-mode package, so I require :noh here~