Merge pull request #144 from tribal-tec/master

Fix syntax error
PackageConfig: only print success status once
Merge pull request #145 from eile/master

PackageConfig: only print success status once
Flatten git externals in release branches
Make snapshot and module targets more robust
Add warning for common user error
Merge pull request #146 from eile/master

Add warning for common user error
Add changes file
Merge pull request #147 from eile/master

Add changes file
Rename
Update CHANGES.md
Merge branch 'master' of https://github.com/Eyescale/CMake
Install symlinks relative, not absolute

This is necessary to fix artifact copy in Jenkins. Besides, the
symlinking on Unix for the different SO versions of libraries
is also based on relative symlinks.