Replace org.json by elemental.json

Include only the elemental.json stuff for JVM needed to run
GQuery JsonBuilders in server side without depending on anything but
gwtquery.jar.
Add varargs Node selector
Tests
Fixed pom for CI
Revert mode
Merge pull request #308 from ArcBees/mmc_try_fix_ci

Fixed pom to allow CI to run tests
Merge pull request #300 from manolo/master

Replace org.json by elemental.json
Merge pull request #307 from ArcBees/spg_node_multi_selector

Add varargs Node selector
Improved filter performance on simple attribute selectors