Now the generated logic tree only consider the relevant tectonic region types
Fixed a bug when setting root_branchset
Merge pull request #1431 from gem/use-only-source-trts

Use only the relevant tectonic region types to build the GMPE logic tree
Merge branch 'master' of github.com:gem/oq-engine into cleanup-of-the-filtering-et-al
Reflected the API change for the filtering function in hazardlib