Implement basic percentage calculation for wifi_perc. With this
commit, the function returns correct percentage, since the max
of what /proc/net/wireless returns is 70.
For multiple reasons the program is now split:
- Make future porting to OpenBSD easier
- Assign header includes to individiual functions
- Make future program extensions easier
- Recompile only changed parts
Aaron Marcher
parazyd
Laslo Hunhold