Add README and fix up package configuration

I renamed the package to match the repo name and fixed the repository URL,
which was recently changed
Merge pull request #1 from jwalgran/topic/fixup-package

Add README and fix up package configuration
Initial implementation of the filter to SQL converter

Generating filtered tiles requires converting the standard OTM2 filter
syntax into a Postgres-compatible WHERE clause.

I included documentation generated with docco.
Merge pull request #3 from jwalgran/topic/filter-to-sql

Initial implementation of the filter to SQL converter