datetime: add -lm to libraries
info: Remove GNOME version data parsing code

We don't use this anymore.
info: Remove PackageKit-based updates UI

We don't use PackageKit, so we don't use this. We'll add our own OSTree
updater checker here.
info: add a way to check for manual updates

Coordinate with the OSTree daemon to manually check for available
updates and possibly install them.
Merge pull request #20 from endlessm/shell/3678-v2

Shell/3678 v2
Prepare for translations for manual OS update feature

[endlessm/eos-shell#3678]
Add ostree-daemon.xml to EXTRA_DIST

[endlessm/eos-shell#3678]
info: don't change state before asserting

Setting priv->ostree_activated to TRUE will change the interactive-ness
of the state; don't do that before asserting that the state we got here
with was interactive.

[endlessm/eos-shell#3678]
Merge pull request #21 from endlessm/shell/3678-fix

info: don't change state before asserting
New translations from Transifex