Apply Lang::createHandle to params' field handle (#2894)
Apply Lang::createHandle to params' field handle (#2894)

When params are added to a page, the field handle is popped off and re-added later, because General::createHandle would strip '.'. This, however, means that only the first part of the parameter is run through Lang::createHandle.

Re: #2892
michael-e/symphony-2,symphonycms/symphony-2,bauhouse/sym-todo-list,michael-e/symphony-2,symphonycms/symphony-2,bauhouse/sym-todo-list