[giac] improve Simplify / TrigSimplify

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24923 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Textfields for Touch, silent infobar

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24924 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Missing part of previous commit

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@24925 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e