Fix a hanging issue with Concordance tool

This fixes FWNX-1036 (and possibly other issues) in which the program
hangs in the Concordance tool due to a disposed PaneBar still being in
a PaneBarContainer's Controls list.

Change-Id: I48b8c61a8cc57ff46f36bb318946c372391b060a
Fix a crash in typeahead in various list item fields

This fixes the crash reported in FWNX-1012.  It does nothing to
provide a Mono/Linux specific implementation of the desired
behavior, however.

Change-Id: Idbd57ec255f3390a9411c2b8d5e7196229cf518a
Fix comparison to allow stable RBTree insertion/retrieval

In the Mediator, colleages are saved in a dictionary, for which Mono
uses a RBTree internally.  The comparison function defined uses the
GetHashCode() method on the objects implementing each colleague.  It
could happen that a colleague could get stored in the dictionary that
could never be retrieved after other colleagues were stored in certain
orders due to arithmetic overflow in the comparison function.  This is
the root cause of the bug reported in FWNX-896.

Change-Id: Ie7aee60b089db55acb14735605bac0cc548a5beb
Merge branch 'release/7.3-gial-Linux' into develop

Change-Id: I5d7056fce47a2e50050d698a23afad0c52a57c33