Workaround to make some loci work

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34261 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
#3392 web: Rows are selectable (simple select)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34262 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Wait for ImageElement to complete before create the alpha texture

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34263 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e