LazActiveX: Improvements. Issue #25908, patch from David Zimmer

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@44518 4005530d-fff6-0310-9dd1-cebe43e6787f
LazActiveX: improve memory management.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@44519 4005530d-fff6-0310-9dd1-cebe43e6787f
LazActiveX: turn some "var" parameters into normal parameters.

git-svn-id: http://svn.freepascal.org/svn/lazarus/trunk@44520 4005530d-fff6-0310-9dd1-cebe43e6787f