Statusbar: Add network traffic indicator, (1/2):

Thanks to the (unknown) author.

- Indicator:
  - Disabled
  - Traffic download
  - Traffic upload
  - Traffic download & upload
- Show bit or byte values
- Hide the indicator on no traffic

Additional changes:
- Show/hide traffic icon
- Traffic text color
- Traffic icon color

- Add reset to Android default, to support themes,
  (text color will be loaded from SystemUI,
  as the network traffic indicator isn`t a part of CyanogenMod,
  CM default color for the status bar clock will be loaded)
- Add reset to DarkKat default

Change-Id: If4e73856f764f2c0f6f7ccb9a6588d8ba34640af