Ticket #3301: forcing layout to fix a bug

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25641 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Removed unused variables, fixed infinite loop when the EV is 0x0, made the code more readable

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25642 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
implemented missing method

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25643 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] adding arbint, arbconst to cas parser

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25644 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e