Path for Testfiles (MSI: Test creating a package)

[Detlef Riekenberg]

Hi
After reading reading this commit, ....
> ChangeSet ID:	20009
> Added files:
>    dlls/msi/tests : package.c
> Test creating a package.
> Patch: http://cvs.winehq.org/patch.py?id=20009

... i Suggest that:
- all directories and files for tests  should be created in
  "%TEMP%\winetest" 
- we modify "wine/tests.h" to get this path and 
  check for path and name overflows (MAX_PATH and nesting level).

"c:" could be readonly or absent/hidden
Any comments please.