update build.xml to set version to 0.3.0
update add-ons xml in preparation for 0.3.0 release
update travis-ci built status to reference this branch
Update README.rst
Update USAGE.rst

Small changes to wording on the documentation.
Update USAGE.rst

Changed style for consistency
Update USAGE.rst

Added two known limitations.
Update USAGE.rst

Bolded the mention of accepting the license.
update travis-ci status image to reference master branch, in preparation for finishing release
Merge branch 'release/0.3.0' into develop