BUG: fix wrong gcc version check

probably irrelevant by now, but emits a warning during compilation.
Merge pull request #3807 from juliantaylor/gcc-check

BUG: fix wrong gcc version check
Fix platform detection for intel platform where get_platform() returns a string ending in x86_64, for instance 'macosx-10.8-x86_64'.
Merge pull request #3818 from lxbarth/master

BUG: fix platform detection for intel platforms