Merge pull request #93 from compiled/master

Fixed bug regarding routing and the query string
Changing "is_null($var)" calls to (null === $var)
Micro-optimization, but the tests pass... so yea
This closes #94
Merge branch 'null-speed-up'
Moving the contributing information to its own file

This enables a reminder message on Github pull request/issue creation
through CONTRIBUTING file detection:
https://github.com/blog/1184-contributing-guidelines
Merge branch 'doc-update'
Adding build status indicator from Travis-CI
to the README
Merge branch 'build-status-tag'
Added support for multiple headers.