Fix "multiple definition" error in downstream projects
Merge pull request #126 from bilgili/master

Merging subproject support
Add PersistentMap::handles( uri )
Merge pull request #129 from eile/master

Add PersistentMap::handles( uri )
Fix Jenkins
Merge branch 'master' of https://github.com/Eyescale/Lunchbox
Bump CMake subtree
Fix travis
Fix build with boost 1.56
Merge pull request #130 from eile/master

Fix build with boost 1.56
Boost dependencies are expilictly given