package_manager.py: Allow multiple regexps in PACKAGE_EXCLUDE_COMPLEMENTARY
The PACKAGE_EXCLUDE_COMPLEMENTARY variable can currently only contain
one regular expression. This makes it hard to add to it from different
configuration files and recipes.
Allowing it to contain multiple, whitespace separated regular
expressions should be backwards compatible as it is assumed that
whitespace is not used in package names and thus is not used in any
existing instances of the variable.
After this change, the following three examples should be equivalent:
