Fixes #566 configurable label decorations for changesets
Was already merged in Bitbucket before import, marked as merged by the import user
- Starting 'issue566-configurable-label-decorations-for-changesets' branch.
- Minor: updated maintenance notes.
- Added a section to the label decoration preference page for configuring changeset labels.
- Code cleaning: removed references to the built-in hg executable.
- Added branch information to the default syntax for changeset labels.
- Minor: commenting.
- Extracted the interpretation of label syntaxes to a utility class. +Tests. +Added support in project labels for newly-added changeset information. +Deprecated preference PERFORMANCE_PROJECT_SHOWS_CHANGESET.
- Added a dialog for selecting a label decoration variable.