RBM should cache the result of lsb_release

I noticed that RBM continuously calls lsb_release -irc.

Currently, lsb_release calls apt-cache on my Debian system, and it fills /var/cache/apt with temporary pkgcache.bin and srcpkgcache.bin and does not delete them.

Of course, this is Debian's bug (I will verify if one exists, or open one in case), but it is still a problem for us: a lsb_release -irc call takes almost a second, and it is called a crazy high number of times!

time lsb_release -irc
Distributor ID:	Debian
Release:	testing/unstable
Codename:	n/a

________________________________________________________
Executed in  908.69 millis    fish           external
   usr time  841.37 millis  336.00 micros  841.03 millis
   sys time   67.85 millis    0.00 micros   67.85 millis

Therefore, my proposal is to cache this value.