[1/2] SystemUI: Update network traffic indicator

Android measures the amount of data transferred in bytes,
however, by convention, data rates should be measured in bits
per second.

*Convert the change in total data and time to bits and seconds,
and then divide the amount transferred by the number of
seconds that have elapsed.

*Update the labels and have them use the correct SI prefixes.

*Factor out or add @hide to public methods and constructors

*Remove all Runnables and Messages from Handler queue when
disabled

*Minor formatting changes to stay consistent with Android's
code-style guidelines.
https://source.android.com/source/code-style.html

PS2: Set maximum digits to prevent it from filling the statusbar
PS3: Rebase
PS4: Add ability to display either bits or bytes

Change-Id: I9add610a8d14f5a48f2af0a82ced0c186224e282
CM11 Themes: Common overlay for sharing resources. [1/2]

This patch will allow themes to contain common resources
which can be shared by all overlays.

Common resources will reside in assets/overlays/common and
can be referenced by other overlays.

Common resources will be referenced using the common package
name, i.e. To reference the common drawable some_drawable for
com.example.theme the theme designer would use
"@*common:drawable/some_drawable"

Change-Id: I395b6bd5eae91b00265a8e9221856ef7bf5d115a