[ros-svn] 13656: Don't use svn command line tool to getrevision number

[Ge van Geldorp]

>   From: gvg(a)svn.reactos.com
>  
>  Don't use svn command line tool to get revision number
>  XML code stolen from the xmlbuildsystem branch, we need
>  to merge this when merging the xmlbuildsystem back into trunk 
If you get weird error messages when svn up'ing in reactos/tools on Linux,
remove reactos/tools/buildno. "reactos/tools/buildno" used to be an
executable, now it's a directory. Doing a "make clean" first and then a
"svn
up" works ok. Windows shouldn't be a problem, there is no name conflict
there as the old executable was named buildno.exe.

Gé van Geldorp.