suse vag-build: add CPAN_ADDON; upgrade perl to 5.18.2

- If CPAN_ADDON is set in Makefile.local, the listed CPAN modules
  are added to the perldeps rpm package.
- upgrade perl version in perldeps to 5.18.2
remove Build.PL from Mason client
copy client prereqs to core
suse vag-build: fix mason pkg build