Some members and functions were named in different ways, now the naming scheme is a bit more unified. Also changed some types to size_t where negative values don't make sense.
This will make it easier to integrate projectM into C applications and also removes potential issues of STL/C++ version differences between host and library.
Changed visibility of all symbols except the C API to "hidden". This effectively prevents the C++ API from being used in the shared library.
Added an option "ENABLE_CXX_INTERFACE" to re-enable the old export behaviour, displaying a prominent author warning after configuring the build if enabled.