WIP background app passes user_data arg
WIP do not use glib timer
WIP whitespace
WIP do not require reactive mainloop at cpu keepalive start

The users drop in glib timeout replacements could block and thus the
keepalive might never get active.

Also means the dbus connection must be established immediately,
instead of delaying until needed - dbus connection must be flushed
to ensure that data is flowing towards mce before callback is
entered.
WIP pass cpu keepalive context id to mce too
WIP query cpu keepalive renew period from mce
WIP whitespace