#3557 fix && expressions are not wrapped in KeepInput anymore

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@28532 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Some extra enhancements in LaTeX output


git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@28533 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
remove unused code, minor fix for #3557

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@28534 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Ticket #3516: undoing r28518, as this is not the real solution, and introduces new bugs (also see #3171)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@28535 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e