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/common/task.py

@@ -25,9 +25,7 @@ class LoggableMultiSeparateTask(task.MultiSeparateTask):
 
 
 class PopenTask(task.Task):
-    """
-    I am a task that runs a command using Popen.
-    """
+    """I am a task that runs a command using Popen."""
 
     logCategory = 'PopenTask'
     bufsize = 1024
@@ -44,7 +42,7 @@ class PopenTask(task.Task):
                                          stdout=subprocess.PIPE,
                                          stderr=subprocess.PIPE,
                                          close_fds=True, cwd=self.cwd)
-        except OSError, e:
+        except OSError as e:
             import errno
             if e.errno == errno.ENOENT:
                 self.commandMissing()
@@ -88,7 +86,7 @@ class PopenTask(task.Task):
                 return
 
             self._done()
-        except Exception, e:
+        except Exception as e:
             logger.debug('exception during _read(): %r', str(e))
             self.setException(e)
             self.stop()
@@ -118,31 +116,29 @@ class PopenTask(task.Task):
         # self.stop()
 
     def readbytesout(self, bytes):
-        """
-        Called when bytes have been read from stdout.
+        """Call when bytes have been read from stdout.
+
+        :param bytes:
+        :type bytes:
         """
         pass
 
     def readbyteserr(self, bytes):
-        """
-        Called when bytes have been read from stderr.
+        """Call when bytes have been read from stderr.
+
+        :param bytes:
+        :type bytes:
         """
         pass
 
     def done(self):
-        """
-        Called when the command completed successfully.
-        """
+        """Call when the command completed successfully."""
         pass
 
     def failed(self):
-        """
-        Called when the command failed.
-        """
+        """Call when the command failed."""
         pass
 
     def commandMissing(self):
-        """
-        Called when the command is missing.
-        """
+        """Call when the command is missing."""
         pass