* ConfigTest: Add some additional comment parsing tests
* Config: Drop backslash in invalid escape sequences in subsections
* Config: Match C git behavior more closely in escaping values
* TestRepository: Allow setting explicit Change-Id
* TestRepository: Ignore existing Change-Id in message
* TestRepository: Support committing to unborn symref
* TestRepository: Expose some getters for CommitBuilder
* TestRepository: Add methods to amend commits or refs
* TestRepository: Add a reset method to move HEAD around
* TestRepository: Optionally insert Change-Id in commit message