[Cin] Latex and Manual

[Andrea paz]

GG's response to Glenn in the forum seems
(https://www.cinelerra-gg.org/forum/help-video/hotkey-to-deselect-all-groups/#post-698)
so clear and interesting to me that I propose to include it in the
latex manual:

GG on selection's method: [at the end of paragraph 5.5; as a final
summary. then becomes a new paragraph 5.6 and the following are moved
to 5.7, ... etc. I'd like to name the section: "Good Guy speaks:"]
There are several "selections" method.  First, in the olden days,
there was the column oriented timeline drag selection.  That manifests
in 1 of 3 ways.  a highlighed vertical column, a single flashing line,
or the blue line region between the [in and ]out marker labels.  When
the drag column is in use, it has the highest precedence and is used
for selection.  When the column is a single line, then the fall back
selection is the [in/out] marker region, if they are set.  When they
are not set, and the cursor is flashing, then the selection start=end
and the selection is empty, but it does have a position on the
timeline which can be used for editing.  This is input for the
vertical style cut/paste drag/drop editing.

Now, in the new "group" world, there are "edit" selections.  These are
created by using the drag/drop cursor and clicking edits to toggle
select/deselection.  These are input to a different (more modern) set
of cut/paste/overwrite drag/drop editing.  These are the set of
operations you see when you click an edit with the middle mouse
button, and are available using the hot keys which are more like text
editor, ^x=cut, ^c=copy, ^v=paste, and so on...   The delete key is
not hooked to these operations.  It is hooked to the cursor selection
region.
If there are In/Out points, they enter the selection priority queue
between the column selection and the cursor only. You can see the
region selection blue line across the timebar.  This means that when
the cursor selection is empty, the in/out selection will be used.