avocado/utils/process.py: drop __str__ and __repr__ of command results and errors

There's just so much implicit conversion on those methods that makes
them an enourmous source of errors (including UnicodeErrors).  The
information is still all there, and users are free to interpret them
as they see fit.
Signed-off-by: NCleber Rosa <crosa@redhat.com>

avocado/utils/process.py

@@ -82,23 +82,6 @@ class CmdError(Exception):
         self.result = result
         self.additional_text = additional_text
 
-    def __str__(self):
-        if self.result is not None:
-            if self.result.interrupted:
-                msg = "Command '%s' interrupted by %s"
-                msg %= (self.command, self.result.interrupted)
-            elif self.result.exit_status is None:
-                msg = "Command '%s' failed and is not responding to signals"
-                msg %= self.command
-            else:
-                msg = "Command '%s' failed (rc=%d)"
-                msg %= (self.command, self.result.exit_status)
-            if self.additional_text:
-                msg += ", " + self.additional_text
-            return msg
-        else:
-            return "CmdError"
-
 
 def normalize_cmd(cmd, encoding=None):
     """
@@ -357,19 +340,6 @@ class CmdResult(object):
             return self.stderr
         raise TypeError("Unable to decode stderr into a string-like type")
 
-    def __repr__(self):
-        cmd_rep = ("Command: %s\n"
-                   "Exit status: %s\n"
-                   "Duration: %s\n"
-                   "Stdout:\n%s\n"
-                   "Stderr:\n%s\n"
-                   "PID:\n%s\n" % (self.command, self.exit_status,
-                                   self.duration, self.stdout, self.stderr,
-                                   self.pid))
-        if self.interrupted:
-            cmd_rep += "Command interrupted by %s\n" % self.interrupted
-        return cmd_rep
-
 
 class FDDrainer(object):