Merge pull request #16 from rshah/master

added original authors in elarun theme
and some more fixes for the elarun theme
Maui: Add keyboard navigation.
Add uninstall target.
ImageButton: Add disabled and pressed states, enable triggering by keys.
Elarun: Convert image to image button.

Enables proper mouse cursor support, mouse over effects and triggering
by space and return keys.
ImageButton: Clean up state handling code.
Button: Use the same state handling logic with ImageButton.
Add namespace to the header guard.
Make systemd optional.
UserModel: Rename userName -> name.
Add a power management interface with configurable backends.
Fix error preventing login.
Update TODO.

We can handle suspend and resume through systemd and upower.
Add cmake flags to enable systemd or upower support, update README.
Update PKGBUILD.
Elarun: Add sleep and hibernate support.
Components: Use behaviors instead of transitions.

Behaviors are more concise and we don't use any feature of transitions
anyway.
ComboBox: Use builtin ListView functions instead of custom ones.
ComboBox: Update current item only when clicked or entered.
ComboBox: Load correct item on startup.