Prevent property editor from throwing exceptions when creating property windows. Errors are reported on the console, but should not break the normal flow of execution.
Prevent property editor from throwing exceptions when creating property windows. Errors are reported on the console, but should not break the normal flow of execution.

git-svn-id: 80d932a80928324f4d3d71af042e652e41ead033@2203 a8418922-720d-0410-834f-a69b97ada669

amolenaar/gaphor,amolenaar/gaphor