Convert docstrings to reStructuredText

This commit also includes:

  - whitespace / code formatting fixes
  - slight syntax related changes: except <exception_name>, e -> except <exception_name> as e
  - 3 pointless instructions instances have been rewritten [sorted] (spotted by semi-automatic check)

The unrelated changes shouldn't have any real impact on whipper's behaviour.

whipper/program/soxi.py

@@ -10,19 +10,29 @@ SOXI = 'soxi'
 
 
 class AudioLengthTask(ctask.PopenTask):
-    """
-    I calculate the length of a track in audio samples.
+    """Calculate the length of a track in audio samples.
 
-    @ivar  length: length of the decoded audio file, in audio samples.
+    :cvar logCategory:
+    :vartype logCategory:
+    :cvar description:
+    :vartype description:
+    :cvar length: length of the decoded audio file, in audio samples.
+    :vartype length: int or None
+    :ivar logName:
+    :vartype logName:
+    :ivar command:
+    :vartype command:
+    :ivar error:
+    :vartype error:
+    :ivar output:
+    :vartype output:
     """
+
     logCategory = 'AudioLengthTask'
     description = 'Getting length of audio track'
     length = None
 
     def __init__(self, path):
-        """
-        @type  path: unicode
-        """
         assert type(path) is unicode, "%r is not unicode" % path
 
         self.logName = os.path.basename(path).encode('utf-8')