setup: Bumped version: 0.1.20.

setup: Bumped version: 0.1.19.

setup: Bumped version: 0.1.18a0.

setup: Bumped version: 0.1.17a0.

setup: Bumped version: 0.1.16a0.

setup: Bumped version: 0.1.15a0.

setup: Bumped version: 0.1.14a0.

setup: Bumped version: 0.1.13a0.

Issues Dav1dde#57, Dav1dde#59 and Dav1dde#61.

Minor fixes, added --local-files and --omit--khrplatform.