[#6480] Add trac ticket importer plugin

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6480] Add trac project and wiki importers; refactor bases

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6480] Remove whitespace from shortname; use autofocus

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6480] TracExport bug fixes

- Pass in options explicitly instead of attempting to read from a
  non-existent global object.
- Improve logging.
- Fix infinite loop bug.

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6480] Importer bug fixes

- Normalize trac urls
- Flush new app configs and related objects before importing artifacts
- Add options needed for WikiExporter

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6480] Initialize classes to prevent exc if no href

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6480] Fix tests to match refactors

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6480] Add tests for Trac ticket importer

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6480] Add tests for Trac wiki importer

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6480] Refactor import_tool() params

- project and user are the only guaranteed params for every
  importer, and should therefore be the only positional args
- All other args to import_tool, even project_name (which refers
  to the name of the project being imported), should be passed
  by keyword.

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>
[#6480] Moved Trac wiki importer to separate package

Signed-off-by: Tim Van Steenburgh <tvansteenburgh@gmail.com>