Do not require ci:ignore-count, when using ci:skip-build in a MR that
has change a lot of packages. If the user already supplies ci:skip-build
then we can safely assume that we don't to check the package count.
Fixes#267
Make sure that changed aports always have a higher version than what is
currently in master. This check can be skipped with ci:skip-vercheck (in
square brackets).
Related: #187
Move most code from build_changed_aports.py to common.py. Another patch
will follow soon, which uses common.py to check the versions of changed
aports.
Related: #187
