Add team support for Bitbucket repositories.
The new Bitbucket hosting service rewrite, which brought along Git

support, only worked for personal acounts. It didn't support team

accounts.
Now, Bitbucket supports two types of plans: Personal, and Team.

This works much like the various plans for GitHub. Depending on the one

selected, we configure requests against the repositories differently.

For personal accounts, the repository owner name in the URL is the

username of the owner, For team accounts, it's the team name, which is

requeste during configuration.
This works with existing configurations. It's assumed that any Bitbucket

repository configuration without an explicit plan set is a personal

account.

Tested with an existing repository that didn't have a plan set. I could

view old diffs and upload new ones. Viewing the repository settings worked,

as did reconfiguring the repository.
Created a new personal Git repository. I was able to create and view review

requests with diffs.
Tested the same with a team Git repository.
Unit tests pass.