[Dev] Fixed a few small bugs in the request interpreter command and associated BOM.

The ResultCombination object was global, for the whole travel query.
It is now created for every travel query slice.

The travel request interpreter now seems to work.
Merge branch 'trunk' into releases
[Release 0.5.3] Release of version 0.5.3.
[Doc] Bumped the release number for the next time.