Fully integrates svn/dav apache authentication
This patch provides:
- User authentication based on the Redmine authentication module (including external source, such as LDAP) via the Redmine WebService. The password is ciphered in AES for the communication
- Depending on their role on the project, users can have read/write access or read only access (new permission commit_repositories)
- A fully configurable cache system has been deployed to improve performance (WebServices are quite slow).