Reorganized the project files and CMakeLists

src/lib/include -> include
src/lib/src -> src
src/creator -> tools/creator
CMake configuration related to samples and creator are in separate CMakeLists.

The main CMakeLists adds the c++11 definition (it probably works only for gcc).
Renamed TagDrawer to DrawTag
Merged the two simple filters into one header file

CachingFilter and Estimator are now in Filters.
Estimator is now called AveragingFilter.
Updated the documentation
Fixed warnings