libpthread-stubs 0.5

Alan Coopersmith (3):

• Build xz tarballs instead of bzip2
• gitlab CI: add a basic build test
• libpthread-stubs 0.5

Eric Engestrom (1):

• pthread-stubs.pc: remove no longer used variables

Mihail Konev (1):

• autogen: add default patch prefix

Peter Hutterer (1):

• autogen.sh: use exec instead of waiting for configure to finish