Makefile.PL: fix typo s/File::Stat/File::stat/

File::stat is a core module while File::Stat is from CPAN. Both conflict on case-insensitive filesystems.
Makefile.PL: File::stat is a runtime dependency

File::stat is used at runtime in
WebService::Rackspace::CloudFiles::Object, so this is not just a test
dependency.
Makefile.PL: require File::stat '1.00' explicitely to exclude File::Stat

... as File::Stat is 0.01
Merge pull request #10 from dolmen/patch-1

Makefile.PL: fix typo s/File::Stat/File::stat/