initial commit of Watirmark::Model::Factory#hash_id

Defines a method on models #hash_id that is designed to be the same random string every time it is generated (given they have the same seed).
fixing not_to raise(SpecificErrorClass) deprecation warning

according to: https://github.com/rspec/rspec-expectations/pull/244, expecting a specific error to not be raised is deprecated and not really a good idea.  Indeed, I found two other testcases where a different error was being raised other than the one we specified.  I will fix those in later commits.
merge local master changes into branch
add additional behavior tests for hash_id and uuid
test cleanup - setting UUID was causing the Traits test to fail
add arguments to hash_id to change the size
change encoding so this will work on Ruby 1.9.3
Ruby 1.9.3 and 2.0 compute hashes differently
merging in hash_id_feature
bump version