[source/git] Rename `invalid_branches` setting

The `settings` hash added an extra level of depth that's really not
necessary for configuring a source since it can handle arbitrary keys.
This commit shifts the control for invalid branches to a top level
source setting.
Merge branch 'issue/1.3.x/git-source-invalid-branch-setting' into 1.3.x
[doc] (GH-112) Add documentation for 'deploy module -e'
Update CHANGELOG.mkd and version for 1.3.0rc1
Merge branch 'release/1.3.0' into 1.3.x