Support for running different commands on keydown and keyup

[cork]

Currently there is only possible to bind a command for keydown.

If it was possible to bind two commands that was triggered on down and up one could use a g13 key as mod key to have additional button actions (for games that have a ton of shortcuts).

Been thinking about a decent syntax, but isn't sure bind g20 !profile extra_actions !profile normal_actions feels convoluted but I can't think of a better one.