source-cleaning (#3530)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@29583 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Ticket #3735: \textsf{} and/or ggb XML serif=true forces sans-serif permanently (this is still better than the previous state of the things)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@29584 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
#3013 query for url paramters

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@29585 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e