implemented the netspeed functionality for openbsd.
furthermore the static keyword was removed of the interval variable in
config.def.h for usage as extern variable.
when an AC is connected apm_info shows a non-valid value for remaining
minutes. it was decided that in that case the function should return an
empty string.
Implementation of a battery_remaining function which returns the
remaining battery time in HH:MM format. Linux function still needs
implementation.
Move common code to load_apm_power_info
The swapctl(2) function fills the swapent struct with 512KB blocks.
As we want to display in GB, i just modified the calculation for this to
get the expected output.
