Various Windows fixes:

Various Windows fixes:
* Restore correct code to detect a bad drive on Windows.
* Update the bad drive error message to include the target name.
* Update SConfTests.py to print the config.log on error.
* Fix the smart_link() error message to not use repr() of a path so
  escaping the \ separators on Windows doesn't interfere with regex matchs.
* Update regexes in test/VariantDir/reflect.py to accomodate command-line
  re-ordering to put the /OUT: first in the line.
* Explicitly check for smart_link() messages even on Windows.

git-svn-id: http://scons.tigris.org/svn/scons/trunk@3905 fdb21ef1-2011-0410-befe-b5e4ea1792b1