Make it possible to store the kstack or ustack in a map (as value, not key).

Make it possible to store the kstack or ustack in a map (as value, not key).
Additionally fix the bacmp() function to work on integers and strings.
bacmp() is used when maps are printed out since the output is sorted by value.
Also adjust the rule parser to look into correctly into if branches to figure
out which values to request from the kernel.
OK kn@