batman: FreeBSD and OpenBSD (sysctl)
After the work on the sysinfo gadgets for Linux the BSD variant
code was a little bit of an afterthought. These changes provide
us with unlimited battery/sysinfo gadgets and reliable status
for our battery or batteries and our power supply.
This patch allows us to add and remove (many) batman gadgets to
the desktop without negatively affecting existing instances.
It also takes into account additional sysinfo gadgets that include
a batman instance.
Iterating through the existing array of sysinfo gadgets to find
multiple instances and apply changes it not ideal but it does
not affect the Linux code, and keeps this change relatively
Tested on FreeBSD and OpenBSD with various hardware setups.
Thanks to Peter2121 (Quelrond) for his testing.
There is work to now improve batman's Linux behaviour to match that
of the behaviour on BSD systems.