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/__get_hash_code.py

@@ -0,0 +1,31 @@
+import hashlib
+import sys
+
+
+"""Print on stadard output the size in KB and sha256 codes of a list
+of command line-provided file names."""
+
+print()
+
+try:
+    fnames = sys.argv[1:]
+except Exception:
+    print("Provide a valid filename.")
+    exit()
+
+for fname in fnames:
+    try:
+        with open(fname, mode='rb') as f:
+            target = f.read()
+    except Exception:
+        print("File not found")
+        exit()
+
+    code = hashlib.sha256()
+    code.update(target)
+    hash_code = code.hexdigest()
+
+    print("File name:", fname)
+    print("Size (KB):", round(len(target) / 1024, 3))
+    print("Hash code:", hash_code)
+    print("-" * 80)