Change Git Validation to convert https and http protocols for git and web urls to git protocol

Ohloh SCM converts the read_only GIT url in format of https://<SOMETHING>@github.com/<PATH>.git to the git protocol.

This change converts HTTP for the git clone URL as well as HTTPS and HTTP for web URLS to the git protocol. 

Because this change works for read-write as well as read-only github URLs, the name of the method in the Git validator has been changed from "read_only_url" to "normalize_url"