Servatrice icon now gets created in windows start menu.

just avoid deleting servatrice.ini, if the user manually made one from
the servatrice.ini.example

Package the correct cpack’s temporary directory

* Move all cmake-related files in a new “cmake” folder
* move nsis files in there, too, since they are templates parsed by cake
* retrieve git version once when cmake is run, and use it for both
creating version_string.h/cpp and for package naming

Putting user stuff in program files is bad

This should prevent deleting old deck files