Patch by Jürgen Fischer: don-t-use-file-locking-on-windows and add CMake...

This pullrequest applies a patch made by Jürgen Fischer in order to make SOSI files readable for QGIS 2.4, which uses multithreaded rendering and therefor had problems with locking of the SOSI index files on Windows (while file locking is not applied on other OSes). Furthermore he added a CMake build.