Move version number from __init__.py to __main__.py

This will allow the access from outside the package. setup.py and the
Makefile can use this version number. The __init__.py script imports
the version number, so the module will have the __version__ variable
as usual.

src/revpicommander/__init__.py

@@ -3,4 +3,5 @@
 __author__ = "Sven Sager"
 __copyright__ = "Copyright (C) 2023 Sven Sager"
 __license__ = "GPLv3"
-__version__ = "0.9.10rc3"
+
+from .__main__ import __version__

src/revpicommander/__main__.py

@@ -3,6 +3,7 @@
 __author__ = "Sven Sager"
 __copyright__ = "Copyright (C) 2023 Sven Sager"
 __license__ = "GPLv3"
+__version__ = "0.9.10rc4"
 
 # If we are running from a wheel, add the wheel to sys.path
 if __package__ == "":
@@ -16,7 +17,14 @@ if __package__ == "":
 
 if __name__ == "__main__":
     import sys
-    from revpicommander.revpicommander import main
 
-    # Run the main application of this package
-    sys.exit(main())
+    if len(sys.argv) == 2 and "--version" in sys.argv:
+        # Catch --version, if this is the only argument (sys.argv[0] is always the script name)
+        print(__version__)
+        sys.exit(0)
+
+    else:
+        from revpicommander.revpicommander import main
+
+        # Run the main application of this package
+        sys.exit(main())

src/revpicommander/proginit.py

@@ -89,11 +89,12 @@ parser.add_argument(
     "-f", "--logfile", dest="logfile",
     help="Save log entries to this file"
 )
-
 parser.add_argument(
     "-v", "--verbose", action="count", dest="verbose", default=0,
     help="Switch on verbose logging"
 )
+# The __main__ script will process the version number argument
+parser.add_argument("--version", action="store_true", help="Print version number of program and exit")
 pargs = parser.parse_args()
 
 # Check important objects and set to default if they do not exists