Support "Recommends" RPM dependencies

Support "Recommends" RPM dependencies

This requires updates of obs-build (for GBS/OBS):
https://github.com/openSUSE/obs-build/pull/303

and Perl-BSSolv (for OBS):
https://github.com/openSUSE/perl-BSSolv/pull/7

and RPM > 4.12.0 or "Recommends" backported (for OBS/GBS):
https://review.tizen.org/gerrit/#/c/93958/

The issue that we are trying to resolve with these is:
https://github.com/openSUSE/obs-build/issues/302

Change-Id: I579f402a3502c57ca3b2cacfc12a5a3a975aac34
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>