Thank you Andre!

These git diff stats are a bit misleading as a lot of files were removed from the git repo and some 3rd party libraries were added.

properties with a value of null were not being documented

menus to use DDLightbarMenu instead of SlyEdit's own lightbar code.  This
allowed the elimination of most of the rest of SlyEdit's own lightbar code,
reducing the size of SlyEdit.js by about 40Kb.  It also provides some consistency
in behavior by using a common menu component.

Also, to support some additional required behaviors by SlyEdit, added the following
'event' functions to the DDLightbarMenu class:
ValidateSelectItem(pItemRetval): For validating that the user can select an item.
Takes the item's return value, and returns a bool to indicate whether the item can
be selected.

OnItemSelect(pItemRetval, pSelected): A function that is called when an item is being
selected (or de-selected, when multi-select is enabled).  The parameters are the item's
return value and a boolean to indicate whether the item was selected or de-selected.

Also, added an explicit DoKeyDown() function to DDLightbarMenu to support scrolling
the menu down when desired (special case for SlyEdit's quote selection window).

e.g. DIZ's up to 4000 characters are supported.

This won't impact Synchronet as it has a separate signal handling
thread, but we still need to behave properly for processes that
don't.  I'm also saying that ENOMEM does not indicate a disconnection,
though it may be better to pretend it was disconnected...

This reverts commit b76f4695.

Incremented the version to 1.72 and date to 2020-03-04 to be up to date with today's release of SlyEdit.