qmake shouldn't set pdb name by default

qmake always sets ProgramDataBaseFileName to .\ when creating VC project files by default.
This seriously complicates our workflow since pdb files are created in the project directories rather than the target dirs and they are named vcXXX.pdb. This means:

1. people always forget the pdbs when copying libs around
2. this doesn't work out with also having release builds with debug symbols
3. if you want to put several libs in the same folder they all reference the same vcXXX.pdb so there's no easy way to get symbols for all of them
4. you end up with a huge load of linker warnings about missing vcXXX.pdb that can't be disabled

It also doesn't make any sense to set this since the default already creates such a file (plus a proper one in the target dir):
http://msdn.microsoft.com/en-us/library/yd4f8bd1%28v=vs.100%29.aspx