CMake configuration modules (FindAPR, FindAPRUtil, FindSofia), implemented by Vali for the SWIG wrapper are copied over into build/cmake directory.

While this version can be used to build and install the project on Windows and Linux, there are some leftovers which need to be addressed such as:

* APR, Sofia-SIP dlls need to be copied into the binary directory on Windows (either with install or a pre-installation target).
* Missing APR compilation flags on Linux (apr-1-config --cflags)
* Add resource files (.rc) to Windows binaries
* Conditional build (test, client/server,...)
* And probably more ...