Make localisation stand-alone

Background: Currently in order to create a translation of LibreOffice, it is necessary to compile the code with that translation in-place. The compilation process builds the strings directly into a number of binary (and XML) file formats, which are scattered through the source tree. This means, it is impossible to iteratively translate LibreOffice - quickly seeing, and verifying the results of your work. It also makes the complete build slower, and looses a prime opportunity for parallelisation: each language should be able to be built on a separate machine for a separate package. Fixing this requires reading a lot of makefile.mk code, and digging at the localisation tools in localise/ It also requires some work in tools/source/rc/resmgr.cxx and its coupling to rsc/ - the resource compiler (that compiles .src files). We should separate translations from dialog / resource files.

Skills: building, C++