Merge pull request #130 from holtgrewe/hotfix/refinement_bugs

Hotfix with refinement and gaps bug.
[FIX] Fixing bug in test that caused the swift index test to not compile.

Note that it now fails since there is a bug with the swift index search if the pattern is empty.
Merge pull request #133 from holtgrewe/hotfix/swift_test_bugs

[FIX] Fixing bug in test that caused the swift index test to not compile.