Fix a bug in the *.spec files and also apply the following major changes:

- Add support for adding the base folder to PATH.
- Only display one pop up window at a time in order to avoid confusion.
- Add automatic updates feature:
	- Windows and Linux versions will be shipped with an updater program used to
	  update both Artemis and the updater itself.
	- MacOs versions will not have the updater. Instead the user will be asked
	  to download the new software version (if present) via browser.

spec_files/Linux/Artemis_onedir.spec

@@ -12,7 +12,8 @@ SRC_PATH = "../../src/"
 data_file = [
     (f, '.') for f in glob.glob(SRC_PATH + '*.[pu][yi]')
     if f.split('/')[-1] != "artemis.py"
-].append((SRC_PATH + 'cacert.pem', '.'))
+]
+data_file.append((SRC_PATH + 'cacert.pem', '.'))
 
 a = Analysis([SRC_PATH + 'artemis.py'],  # noqa: 821
              pathex=[os.getcwd()],