fixed platform_helper.py msvc_needs_fs test
Merge pull request #691 from TheOneRing/fix-msvc13

fixed platform_helper.py msvc_needs_fs test for python 3
Fix additional range in character class.

The range was added in 7ab6dcbdb6447861eefafc47fc3e10f3273cede2, but that
change only tried to add ! to the character class. Fix by moving '-' to the end
of the class.

Fixes #694.
Merge pull request #695 from nico/norange

Fix additional range in character class.