Revert "Introduce base exception classes"

This reverts commit b744111c80609321e83ddb84975339eba6b89e3c

git-review

@@ -59,11 +59,7 @@ class colors:
     reset = '\033[0m'
 
 
-class GitReviewException(Exception):
-    pass
-
-
-class CommandFailed(GitReviewException):
+class CommandFailed(Exception):
 
     def __init__(self, *args):
         Exception.__init__(self, *args)
@@ -82,16 +78,6 @@ The following command failed with exit code %(rc)d
 -----------------------""" % self.quickmsg
 
 
-class ChangeSetException(GitReviewException):
-
-    def __init__(self, e):
-        GitReviewException.__init__(self)
-        self.e = str(e)
-
-    def __str__(self):
-        return self.__doc__ % self.e
-
-
 def run_command_status(*argv, **env):
     if VERBOSE:
         print(datetime.datetime.now(), "Running:", " ".join(argv))
@@ -875,6 +861,6 @@ def main():
 if __name__ == "__main__":
     try:
         main()
-    except GitReviewException, e:
+    except CommandFailed, e:
         print(e)
         sys.exit(e.EXIT_CODE)

git-review.1

@@ -108,18 +108,6 @@ defaultremote=review
 defaultrebase=0
 .Ed
 .Pp
-.Sh DIAGNOSTICS
-.Pp
-Normally, exit status is 0 if executed successfully.
-Exit status 1 indicates general error, sometimes more
-specific error codes are available:
-.Bl -tag -width 999
-.It 2
-Gerrit
-.Ar commit-msg
-hook could not be successfully installed.
-.El
-.Pp
 .Sh EXAMPLES
 To fetch a remote change number 3004:
 .Pp