Merge branch 'release/0.5.0' into develop
Update project version for further development.
Formatting fix.
Implement has-descendant selector.

Add args and flexibility to select-next-loc.
Add tests.
Add has-child? selector.

Add tests.
Update project.clj for 0.5.1.
Update readme for 0.5.1.
Merge branch 'release/0.5.1'