Use String#to_java_bytes for normal string bodies.
Lock rack integration test to rack-1.4.1.
Add rack-1.4.3 integration test.
Depend on newer version of mini_aether.
Pass through #initialze_copy, #replace to super class implementation in Environment.
Don't store fetched HTTP headers in the fronting hash because it breaks Rails' freezing the hash (this means #delete is also broken).
Remove slow clean_slashes method.
Merge with commonground 'master'.
Use frozen string constants in a few places in Environment and elsewhere, for speed.
Merge pull request #3 from pmahoney/master

A few minor optimizations