Remove release candidate

Still another maven sign fix.

Version 2.0.0-rc1. Shapes (partially addresses brunomnsilva#4, brunom…

…nsilva#34 and brunomnsilva#37), sizes, providers, annotations and minor improvements.

maven-gpg-plugin to 1.6

Release folder deleted.

Fix for brunomnsilva#22. Removing edges is now reflected in the inter…

…nal representation of adjacency.

Fix: (of fix!) labels for vertices and edges are now updated during c…

…alls to

update() or updateAndWait().

Minor fix of CSS warning