Add new timerapplet in c

To replace old timer-applet written in pygtk and not working in 1.6
See https://github.com/mate-desktop/mate-applets/issues/45
Remove old timer-applet
timerapplet: Translate context menu
Merge branch 'dev-timer-applet'

Closes #45
https://github.com/mate-desktop/mate-applets/issues/45