python: Remove --with-wctype-functions flag

This causes functions like string.upper() to misbehave on non-ASCII
characters.  Upstream also advises against it:

  http://bugs.python.org/issue9210
  http://bugs.python.org/issue11309
Re-Revert "Merge pull request #567 from MarcWeber/submit/cmake-improvement"

This reverts commit b08e12b37ae9470c9d8eb8438c21adb8ddbae19e.
Merge master into stdenv-updates