The post-save and post-sync hooks now automatically detect whether the
data directory contains a .git/ directory and skip the commit creation
process if it does not.
The post-save hook and the new pre-load hook now also run
calcurse-caldav in the background if that script is available and the
data directory contains a caldav/ directory.
Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>