Introduce the property its.to.skip

By specifying shell patterns one can disable the matching integrations
now. This is needed because BuildHive seems not to have libstdc++, libm
nor libc available for linking statically via gcc. For now, we can use
the newly-introduced property to skip it0002 on BuildHive.

(In related news, removing the hard-coded 'master' from the BuildHive
job configuration all of a sudden fixed building different branches
and pull request. D'oh.)

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge remote-tracking branch 'origin/master'

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>