#3392 reverting [changeset 34294]

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34295 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
#3392 FunctionInspectorModel fixes

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34296 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] change for #4258
sorta/sortd now sorts complex number (according to real part)
implicit_diff command added
greduce accepts fractions now


git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@34297 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e