Autodetect running programs using regexp

[Pavlo Shchelokovskyy]

It might be useful to include ability to autodetect running programs based on user-provided regular expression.

(My) particular use-case - most of the Steam games I have I play with Xbox controller, and somehow Ubuntu does not count controller events as input, so to prevent my notebook from dimming the screen etc I have to resort to Caffeine when playing games. But I have to manually input names of all corresponding executables of all the games installed, and keep this list updated. Would've been nice to be able to input something like "/SteamApps/.*" so that any program which path matches this regex would trigger automatic enabling of Caffeine.