- Adapt script to the limited Android shell environment.
- Unfortunately, the script returns 0 most of the time because it requires
  precision on the percentage calculation provided by bc. However, bc is not
  available on Android.
  - Something to consider on a later version.
Fix: do not set cpuPercentage to 0 if it's already 0
Merge pull request #9 from lioux/jb-initram-4.2.2-wifi3.4

Adapt proc_cpu_percent.sh script to the limited Android shell environment