Fixed deprecated 'send' call  & windows path issue

-path.join in windows uses backslashes, made staticGzip recognize this.
unit tests to mocha, rewrote assert.response

-Moved /sub to /subdirectory because mimetype was picking up as text/sub
-rewrote helper methods for testing compressed or not compressed
-rewrote assert.response from expresso since expresso was removed
-fixed gzipStatic path identification in windows
Merge branch 'master' of https://github.com/medseek-engineering/connect-gzip

Conflicts:
	test/gzip.test.js
	test/helpers/index.js