Merge pull request #25 from tribal-tec/master

Fix per-project unique prefix dir
Auto-increment package version
Fix auto-increment package version
portfile target name tweak
PackageConfig fix
Add retag target
Revision optimisation
Consistent capitalization
Add file swallowed by git reset HEAD^
Move generic parts from Eyescale/Lunchbox#32 to here
Postpone .spec file generation to allow more generalization
Add doc package component
Cleanup; now set by Builyard