Add Weather Content Provider [5/5]

Use the Weather Content Provider in the cmsdk to pull the
weather data.

However, SystemUI will rely on LockClock to force weather
updates via the new Weather Service, which in turn will
send a broadcast when new weather data is available.

Change-Id: I3c65ea5f4cc297a7944fcdef33f496cdf2d68d0a

SystemUI: Expose weather text colors

Weather text colors in the expanded status bar are hardcoded to
white. Expose these via cm_colors so that themes can color them
however they'd like.

A martini. Shaken, not stirred.

Change-Id: I5e5a738c8b97f556562114a66d102fcb924a0493

SystemUI: Update cached weather data when temperature unit changes

Register an observer to keep track of the temperature unit
selected in settings to update the cached data accordingly

TICKET: CYNGNOS-2694

Change-Id: I92adec20835bcd6d6476d793564300611bcba4a1