There are many ways of iterating over lists in C++/Qt.
In the specific case of QStrings, it is known [1] that using
foreach with const references avoids the creation of new
QString objects in each iteration, reducing the time consumed
by the loops.

[1] https://blog.qt.io/blog/2009/01/23/iterating-efficiently/



Signed-off-by: Anselmo L. S. Melo <anselmo.melo@intel.com>

- Pervasive change to automatically connect to known board types
- Lots of additional changes along with this:
- More exposure of objects/properties to Qml
- Much restructuring in LinkManager and LinkManager clients

- Pervasive change to automatically connect to known board types
- Lots of additional changes along with this:
- More exposure of objects/properties to Qml
- Much restructuring in LinkManager and LinkManager clients

- Pervasive change to automatically connect to known board types
- Lots of additional changes along with this:
- More exposure of objects/properties to Qml
- Much restructuring in LinkManager and LinkManager clients

Fix the corner case of a system running on localhost using the network and the loopback address in parallel. Force it onto the loopback interface.

Link ids were being used interchangeably with the mavlink channel for
the link. Link ids handed out as a numerically increasing integer. Once
the counter went past MAVLINK_COMM_NUM_BUFFERS all hell would break
loose and cause memory corruption.

Also fixed a typo (copy/paste error) in the TCP link settings loading where it was using the UDP port as the default value instead of the TCP port.

This came through google groups and as the change is right where I'd been working, I added it here to avoid collision.

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

Centralize all connecting and disconnecting of links through
LinkManager::[Connect|Disconnect]Link api. Connect/Disconnect no longer
allowed through LinkInterface. This allows creation of new
LinkManager::setConnections[Suspended|Allowed] methods to disallow
connections as needed.

This api doesn’t make any sense given the fact that LinkInterface
signals bytesReceived with the bytes in the signal. Also the reason why
it is never called!

Fix execution context of thread routines - note that this is not quite the architecture the Qt folks intended, but as they admit its the consequence of their architecture.

Converted LinkInterface from a pure-virtual interface into an abstract base class. This centralized the data rate calculation code for all subclasses. Also added the necessary code to provide upstream/downstream data rate calculations for all LinkInterface-derived classes.

Renamed getNominalDataRate to getConnectionSpeed. Also added upstream/downstream data rate functions to all Link classes.

Removed LinkInterface methods which were never being called. Updated various LinkInterface implementation classes to remove the methods. Some methods such as the ones which measure data rates or bits sent/received were implemented in only some of the implementation classes, and in some cases implemented incorrectly. If they were called, the values returned would be incorrect. Although there was some partial implementation for these I removed them as well since in all case they were never being called by any code. In checking Blame, these came across in 2010 and have remained unimplemented since them, so I figure better to clean up than leave crufty, unused, half finished stuff in.