Add a JacksonMatcherFilter.

This new module and class combines the jackson json filter with a Matcher to output only the json that is requested.

Fixes #4
Make JacksonMatcherFilter thread-safe.
refactor to remove ThreadLocal.initialValue.
Merge pull request #17 from PressAssociation/jackson-json-filter

Add a JacksonMatcherFilter.
Make it easier to use partial response with jackson+jaxrs.

This adds a new utility to the jackson module: JacksonFilters - which can be used to configure an ObjectMapper to filter based on a partial response pattern.

I've also added a new module that adds jax-rs specific code to interact with the jackson-jaxrs module, providing a ContextResolver for ObjectMapper that looks for a request parameter and automatically applies the partial response filter for you.

Fixes #5
Reduce visibility of some methods and rearrange inner classes.
Merge pull request #18 from PressAssociation/jaxrs-filter

Make it easier to use partial response with jackson+jaxrs.
com.pa.fire.partialresponse.fields -> com.pa.pr

IDE refactor to move classes from com.pressassociation.fire.partialresponse.fields to com.pressassociation.pr
Add README.md for the jackson json filter project with examples.
Rename the fields-parser module to matcher.
Add NoneMatcher.

This CL adds support for Matcher.none() which is === to Matcher.of("")
Update the top-level readme to include pointers to sub-projects.
First stab at adding Matcher.restrictPath.

Adds unit tests. This will be rebased at some point to be the full commit.