cosmetic: Switch to consistent four-spaces indent; run autopep8

We had a mixture of tab and 4space based indenting, which is a bad
idea.  4space is the standard in python, so convert all our code to
that.  The result unfortuantely still shoed even more inconsistencies,
so I've decided to run autopep8 on the entire code base.

Change-Id: I4a4b1b444a2f43fab05fc5d2c8a7dd6ddecb5f07
diff --git a/pySim/exceptions.py b/pySim/exceptions.py
index f1d1a18..24aff85 100644
--- a/pySim/exceptions.py
+++ b/pySim/exceptions.py
@@ -21,34 +21,40 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
+
 class NoCardError(Exception):
-	"""No card was found in the reader."""
-	pass
+    """No card was found in the reader."""
+    pass
+
 
 class ProtocolError(Exception):
-	"""Some kind of protocol level error interfacing with the card."""
-	pass
+    """Some kind of protocol level error interfacing with the card."""
+    pass
+
 
 class ReaderError(Exception):
-	"""Some kind of general error with the card reader."""
-	pass
+    """Some kind of general error with the card reader."""
+    pass
+
 
 class SwMatchError(Exception):
-	"""Raised when an operation specifies an expected SW but the actual SW from
-	   the card doesn't match."""
-	def __init__(self, sw_actual:str, sw_expected:str, rs=None):
-		"""
-		Args:
-			sw_actual : the SW we actually received from the card (4 hex digits)
-			sw_expected : the SW we expected to receive from the card (4 hex digits)
-			rs : interpreter class to convert SW to string
-		"""
-		self.sw_actual = sw_actual
-		self.sw_expected = sw_expected
-		self.rs = rs
-	def __str__(self):
-		if self.rs:
-			r = self.rs.interpret_sw(self.sw_actual)
-			if r:
-				return "SW match failed! Expected %s and got %s: %s - %s" % (self.sw_expected, self.sw_actual, r[0], r[1])
-		return "SW match failed! Expected %s and got %s." % (self.sw_expected, self.sw_actual)
+    """Raised when an operation specifies an expected SW but the actual SW from
+       the card doesn't match."""
+
+    def __init__(self, sw_actual: str, sw_expected: str, rs=None):
+        """
+        Args:
+                sw_actual : the SW we actually received from the card (4 hex digits)
+                sw_expected : the SW we expected to receive from the card (4 hex digits)
+                rs : interpreter class to convert SW to string
+        """
+        self.sw_actual = sw_actual
+        self.sw_expected = sw_expected
+        self.rs = rs
+
+    def __str__(self):
+        if self.rs:
+            r = self.rs.interpret_sw(self.sw_actual)
+            if r:
+                return "SW match failed! Expected %s and got %s: %s - %s" % (self.sw_expected, self.sw_actual, r[0], r[1])
+        return "SW match failed! Expected %s and got %s." % (self.sw_expected, self.sw_actual)