Added -C command line flag for specifying configuration file location.

radicale/__main__.py

@@ -77,8 +77,16 @@ def run():
         "-D", "--debug", action="store_true",
         default=config.getboolean("logging", "debug"),
         help="print debug information")
-    options = parser.parse_args()[0]
+    parser.add_option(
+        "-C", "--config",default='',
+        help='use a specific configuration file')
 
+    options = parser.parse_args()[0]
+    
+    # Read in the configuration specified by the command line (if specified)
+    if options.config != '':
+        config.read(options.config)
+    
     # Update Radicale configuration according to options
     for option in parser.option_list:
         key = option.dest
@@ -86,7 +94,7 @@ def run():
             section = "logging" if key == "debug" else "server"
             value = getattr(options, key)
             config.set(section, key, str(value))
-
+    
     # Start logging
     log.start()