fixed 91d655597e and 93346654de
gccbuild.bat: reindent
gccbuild.bat: mention the compiler in help
version scripts: make scripts work from every working directory inside the repo
merge build_vs2012.bat into build.bat

Choose compiler with VS2012 and VS2010 switches.
Defaults to VS2010 if omitted.

Merge based on build_vs2012.bat and gccbuild.bat by XhmikosR
make SILENT switch work