Make sure stylebar only shows relevant buttons

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@32724 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Make sure GeoCasCell implements TextProperties so that CAS stylebar works in dev mode

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@32725 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
#4134 Some cleaning and minimal styles set to stylebar

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@32726 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e