Added support for additional HTTP verbs

Support HTTP verbs other than "GET"
Also added support for additional HTTP headers and HTTP Basic
Authentication
use hi.conf instead of a long argument list
Update changelog
Add a test for HTTP Basic Authentication
Add a test for configuring a different HTTP method
Add a test for configuring HTTP request headers
Add a test for configuring a request body
Merge branch 'more_http_input_options' of github.com:bartleusink/heka into bartleusink-more_http_input_options

Conflicts:
	CHANGES.txt
	docs/source/configuration.rst