Ipradar2

- nodes with same geographical location now evenly distributed in circumference
- PLOT_PERIODS parameter added
- popup added to confirm stopping a live capture and exit

- major improvement in memory usage (<160MB in worst-case test-scenarios):
plotMap() is now called every configuration.CHECK_PERIOD_IN_SEC*4.0 i.o. every configuration.CHECK_PERIOD_IN_SEC
This means e.g. every 2 seconds instead of every 0.5 seconds.
The update rate is still very high, as for now we just update static maps.
In future we want to update maps "dynamically".

- added packet statistics on GUI: in, processed, queued.
- improved call to plotMap(): now we update only using flag needUpdate.
Note that it is not worth calling plotMap() in a different thread as we need to
lock the use of node_dict and other data in processPacket() and other concurrent functions,
thus having no benefit in performance. Thus we call it sequentially inside processPacket() when needed.
- tests under high-load conditions result in memory usage of approx. 230MB, but sometimes it may raise up to 500MB.

- use of .join() instead of + for concatenating strings shall prevent memory leaks
- delete map at the end of plotMap() as another measure to prevent memory leaks
- updated TODO.txt
- improved description in READ_ME.txt (to also install whois and traceroute)

NOTE: memory leak when zooming in and out in a "live" map.
This can be resolved in future releases e.g. by opening a "separate" .html map or by finding and solving the root-cause(s).
To get rid of memory leaks completely we may also need to make some major changes like not using lists and dicts anymore (?)

* BUG correction in mainAppWindow.py:
index = self.comboBoxInterface.currentIndex()
replaces:
index = self.comboBoxInterface.getCurrentIndex()
Now it is possible to set the INTERFACE parameter in config.ini without problems.

* Updated READ_ME.txt:
0) ...
You may need to add the installation path to PATH with:
export PATH=$PATH:<installation_path>
e.g.:
export PATH=$PATH:/home/$USER/.local/bin
(you can find the installation path with: whereis ipradar2)

- Moved files in ui folder one level above (and removed ui folder)
- corrected BUG: icons were NOT being found in PyPI package once installed, so we now copy then at startup from the installation folder, as we do e.g. with config.ini