Renamed some spec file names so they don't have question marks in them
Merge pull request #15 from baconpat/windows_compat

Renamed some spec file names so they don't have question marks in them which can cause filesystem issues.
Start on promoting mutable versions out of experimental. Still needs tests and to wrap results in mutable variants where appropriate
Add Marshal support to Hamster::Hash.
Add a test for marshalling Hamster::Set instances. No changes are required here, as we never use Trie#get; all membership tests are done via #any?.
Optimize marshalling of Hamster::Hash by representing it as a plain ruby Hash, rather than a linked list of tuples. This gives a factor of three speedup on a trivial microbenchmark.
Merge pull request #19 from cstorey/marshal-support

Implement marshal support for Hamster::Hash