Merge pull request #1 from jkammerl/groovy-devel

reorganization of includes + include install target
Merge pull request #2 from jkammerl/groovy-devel

fixing library exports in CMakeLists.txt
Merge branch 'groovy-devel' of github.com:sniekum/ar_track_alvar into groovy-devel
renaming PC_LIBOPENNI cmake variable to PC_TINYXML