Also many LinkManager API changes to further isolate all link
management inside LinkManager.

Removed "Clear Text" context menu from roll down dialog
Fixed "Clear Text" context menu in Info Dialog (renamed to "Clear Messages" in the process)

Shrunk the Message drop down dialog a bit.
Made the Message drop down dialog slightly transparent.

I noticed that some times, the disconnect signal would get to the updateConnect button (tool bar) before the link was physically disconnected. That would cause it to count it as a still connected link and get the connect button logic out of sync.
While at it, added an interface to the UDP link to return its configuration instance. That allows the LinkManager to unlink it when disconnecting it.

The goal of this first installment is to organize the code a bit so it's more readable,
clean up a bit of left over cruft, and manage link configurations (and links in general).

Now works for more than Serial links

This function is called automatically when a QSettings object is destroyed,
so is rarely needed to be called explicitly.

There are still some cases where
a QSettings object is passed-by-reference, so there I left the sync() calls as
it's unclear how permanent those objects are and if they'd call sync() before
application shutdown

also adds AMSL output in ft