Make keybinding timeout configurable

[jrop]

I am using vim-mode-plus, and have mapped "j j" to "". This works fine, until I press "j" to move down a line, and Atom waits 1 second to see if I am going to press another "j". There should be a way to configure this, or decrease the timeout.

Also related: #49 (comment)

[xream]

Actually you can set the timeout in your init.coffee: atom.keymaps.partialMatchTimeout = 100