Ticket #3841: adding more getGuiManager() null checks; but this is not enough...

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30096 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Fix for textfields in Android browser

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30097 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
#3842: MultipleOptionsModel and applied for tooltip and reflex angle model

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@30098 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e