Some tidy up in the release build steps, mainly to fix problems with javadoc publication.
Made javadoc push not quiet for now.
Updated the javadoc publication build script. I need to fetch the gh-pages branch first because the git clone done by Travis is shallow and master-only.
Updated the javadoc publication build script. Made the task checkout master at the end for easier testing. Made the task delete only the 'docs/current' dir. This way, old versions documentation is kept.
Bumped version so that it's easier to test javadoc publication.