Code Analyzer crashes when CDS can't be reached

[sjoqvist]

When the CDS goes down, code_analyzer/githomes.py crashes with a message similar to the following.

Sleeping: until next pull 118.103230
Polling https://cds/backups/1... Traceback (most recent call last):
  File "./githomes.py", line 300, in <module>
    gitHomes.poll()
  File "./githomes.py", line 257, in poll
    self.pullBackupsCDS()
  File "./githomes.py", line 219, in pullBackupsCDS
    (responseHeader, result) = h.request( "%s/backups/%d" % ( self.CDSRoot, teamIdx ), "GET", headers={"If-Modified-Since" : self.teamLastModified[ teamIdx ]} )
  File "/usr/lib/python2.7/dist-packages/httplib2/__init__.py", line 1607, in request
    (response, content) = self._request(conn, authority, uri, request_uri, method, body, headers, redirections, cachekey)
  File "/usr/lib/python2.7/dist-packages/httplib2/__init__.py", line 1349, in _request
    (response, content) = self._conn_request(conn, request_uri, method, body, headers)
  File "/usr/lib/python2.7/dist-packages/httplib2/__init__.py", line 1271, in _conn_request
    conn.connect()
  File "/usr/lib/python2.7/dist-packages/httplib2/__init__.py", line 1074, in connect
    raise socket.error, msg
socket.error: [Errno 111] Connection refused

We might want to consider keeping the script alive. However, we then need to decide on the following.

1. Should there be a timeout for when the script should conclude that the CDS won't be coming back and voluntarily stops?
2. Should we log the incident somehow?

Related to #35.