Refactor / shore up message classes

No functional changes, just cleans code for maintainability
Pass request message to response message initializer
Add expiremental 'compressed' messages module

Not standard json-rpc this is a 100% optional module that a
client can simply include to leverage compressed json-rpc
messages.

For a first draft, to compress messages we manually shorted
standard json-rpc header fields and compress / base64 encode
request / notification parmaters and response results.

Again this is expiremental and there is a good possibility
this will change going forward.
Fix json fields ignored in response header analysis

Recent refactoring exposed a bug where response headers
were not being set properly
Move helper modules into lib/rjr/util directory

No functional changes just moves files and updates 'requires'
Small fix to update inspect dispatch method following file move