Add Vim editor

[symjie520]

Hope to add Vim Editor support! Thanks !

[weykon]

YES !!!
Omitted touchpad and efficient coding with Vim are the ultimate in convenient mobile coding.

[bummoblizard]

@weykon I will work on it this today.

[bummoblizard]

60eb17d adds support for vim mode without ex commands and search. I will continue to work on it to support these features.