Perspective eye position related to head tracking (leonar3do)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@33296 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
#4212 Fix: Conditions for GeoNumeric was removed from showLineProperties()

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@33297 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Fix for #4237

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@33298 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e