Merge pull request #23 from pvuorela/master

[nemo-qml-plugin-calendar] Add location support for events
[nemo-qml-plugin-calendar] Emit location changed on all involved events
Remove calendarapi.cpp from header list
[nemo-qml-plugin-calendar] Support setting timespec for event start/end

Allow to create either clock time events or events to local time zone.

API change: replaced related time property setters with explicit
invokable functions.