Clean the build and install pre-pkgs on make clean
Clean the build and install pre-pkgs on make clean

svn path=/trunk/StrategoXT/; revision=7219

Apanatshka/strategoxt,metaborg/strategoxt,lichtemo/strategoxt,lichtemo/strategoxt,Apanatshka/strategoxt,lichtemo/strategoxt,metaborg/strategoxt,Apanatshka/strategoxt,Apanatshka/strategoxt,lichtemo/strategoxt,metaborg/strategoxt,metaborg/strategoxt,Apanatshka/strategoxt,metaborg/strategoxt,lichtemo/strategoxt