CMParts: Network Traffic [3/3]

*) Backport to cm-14.1 (achalmgucker)

*) Adapted to Lineage SDK (bgcngm).

*) Replace autohide threshold selection with the option
   of kb/s, Mb/s (and kB/s or MB/s) (sam3000).

*) Add an option for the user to choose whether or not
   the units are displayed in the statusbar (sam3000).

Change-Id: Idbc0d984177cad284f092339e9b1dc18f8aca9e2