Use modern Python exception syntax

"except Exception as e" instead of "except Exception, e"

This is part of a transition to supporting Python 3.  Python >= 2.6
support "as" syntax.

Note: this removes Python 2.5 support.

Change-Id: I309599f3981bba2b46111c43102bee38ff132803
diff --git a/repo b/repo
index 32cd178..7942851 100755
--- a/repo
+++ b/repo
@@ -185,7 +185,7 @@
   if not os.path.isdir(repodir):
     try:
       os.mkdir(repodir)
-    except OSError, e:
+    except OSError as e:
       print >>sys.stderr, \
             'fatal: cannot make %s directory: %s' % (
             repodir, e.strerror)
@@ -221,7 +221,7 @@
   cmd = [GIT, '--version']
   try:
     proc = subprocess.Popen(cmd, stdout=subprocess.PIPE)
-  except OSError, e:
+  except OSError as e:
     print >>sys.stderr
     print >>sys.stderr, "fatal: '%s' is not available" % GIT
     print >>sys.stderr, 'fatal: %s' % e
@@ -268,7 +268,7 @@
   if not os.path.isdir(home_dot_repo):
     try:
       os.mkdir(home_dot_repo)
-    except OSError, e:
+    except OSError as e:
       print >>sys.stderr, \
             'fatal: cannot make %s directory: %s' % (
             home_dot_repo, e.strerror)
@@ -277,7 +277,7 @@
   if not os.path.isdir(gpg_dir):
     try:
       os.mkdir(gpg_dir, 0700)
-    except OSError, e:
+    except OSError as e:
       print >>sys.stderr, \
             'fatal: cannot make %s directory: %s' % (
             gpg_dir, e.strerror)
@@ -291,7 +291,7 @@
     proc = subprocess.Popen(cmd,
                             env = env,
                             stdin = subprocess.PIPE)
-  except OSError, e:
+  except OSError as e:
     if not quiet:
       print >>sys.stderr, 'warning: gpg (GnuPG) is not available.'
       print >>sys.stderr, 'warning: Installing it is strongly encouraged.'
@@ -392,13 +392,13 @@
   try:
     try:
       r = urllib2.urlopen(url)
-    except urllib2.HTTPError, e:
+    except urllib2.HTTPError as e:
       if e.code == 404:
         return False
       print >>sys.stderr, 'fatal: Cannot get %s' % url
       print >>sys.stderr, 'fatal: HTTP error %s' % e.code
       raise CloneFailure()
-    except urllib2.URLError, e:
+    except urllib2.URLError as e:
       print >>sys.stderr, 'fatal: Cannot get %s' % url
       print >>sys.stderr, 'fatal: error %s' % e.reason
       raise CloneFailure()
@@ -427,7 +427,7 @@
   """
   try:
     os.mkdir(local)
-  except OSError, e:
+  except OSError as e:
     print >>sys.stderr, \
           'fatal: cannot make %s directory: %s' \
           % (local, e.strerror)
@@ -436,7 +436,7 @@
   cmd = [GIT, 'init', '--quiet']
   try:
     proc = subprocess.Popen(cmd, cwd = local)
-  except OSError, e:
+  except OSError as e:
     print >>sys.stderr
     print >>sys.stderr, "fatal: '%s' is not available" % GIT
     print >>sys.stderr, 'fatal: %s' % e
@@ -699,7 +699,7 @@
   me.extend(extra_args)
   try:
     os.execv(repo_main, me)
-  except OSError, e:
+  except OSError as e:
     print >>sys.stderr, "fatal: unable to start %s" % repo_main
     print >>sys.stderr, "fatal: %s" % e
     sys.exit(148)