Add support for the @group annotation and attribute (and aliases)

[chiefmyron]

Add new option to allow organisation of tests via the @group annotation. The @group annotation can be applied to an individual test method, or to an entire test class. If applied to the test class, the group also applies to test methods within that class.

There are additional annotations that are aliases for @group:

• @large is an alias for @group large
• @medium is an alias for @group medium
• @small is an alias for @group small
• @ticket <ticket_id> is an alias for @group <ticket_id>

[chiefmyron]

Reopening, as an issue was discovered where run profiles are not cleared properly when the last method with a specific tag has that tag removed or renamed.