gbuild-to-ide: replacement of the code

this patch do 2 things:
1a) create class testide, a duplicate of
VisualStudioIntegrationGeneration to work on it without touch the
real one
1b) place xcodeintegrationgenerator under testide, and under this
last one all of generators that work yet

Change-Id: Ib678134678ed19de9dcd9d1f47e8e7c16ae59f74
Reviewed-on: https://gerrit.libreoffice.org/33495Reviewed-by: jan iversen <jani@documentfoundation.org>
Tested-by: jan iversen <jani@documentfoundation.org>