removed .gitignore (not needed with catkin)
amcl: changed file layout, exposed libraries and include path
Dependent packages will be able to use amcl as a C++ library this way
calibration: install libs & headers
Merge pull request #37 from dgossow/hydro-devel

amcl refactoring & expose c++ library
Merge branch hydro-layered-costmaps into hydro-devel
 Create README.md and add mailing list link.