fixed styling of input fields in cas
 suppress form submission on enter in cas-cell
 bug in form validation

git-svn-id: https://dev.geogebra.org/internal/moodle/moodle-qtype_geogebra/trunk@3203 872ce066-4876-4fca-a6fc-23b94bf576d1
fixed styling of input fields in cas
 suppress form submission on enter in cas-cell
 bug in form validation

git-svn-id: https://dev.geogebra.org/internal/moodle/moodle-qtype_geogebra/branches/MOODLE_27_STABLE@3205 872ce066-4876-4fca-a6fc-23b94bf576d1
Merge branch 'MOODLE_27_STABLE' of https://github.com/geogebra/moodle-qtype_geogebra into MOODLE_27_STABLE