Equality checking for colors

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@27271 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Debugging for Web graphics

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@27272 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Update internal canvas color when it is changed externaly to match the GGraphics2D color

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@27273 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Giuliano's patch for #509 (PSTricks and PGF/Tikz Output for Inequalities)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@27274 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e