trychange.py: Use urllib2's urlopen() instead of urllib's.

trychange.py: Use urllib2's urlopen() instead of urllib's.

urllib.urlopen() has issues with proxies similar to the ones reported in bug
134165 that are not present in urllib2.urlopen() -- namely, it does not
perform HTTP tunneling with proxy servers when fetching HTTPS URLs.

TEST=Pass --url=https://someurl to trychange.py behind a corporate proxy
R=maruel@chromium.org,iannucci@chromium.org,dpranke@chromium.org
BUG=

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=247914

[M-A Ruel, 2014-01-27 17:45:38]

In practice I only use this code while doing local testing on a temporary local
try server. We do not use it in practice on the dev workflow.

lgtm anyhow.

[commit-bot: I haz the power, 2014-01-27 17:46:32]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/raphael.kubo.da.costa@intel.com/133933...

[commit-bot: I haz the power, 2014-01-27 17:48:21]

Presubmit check for 133933007-1 failed and returned exit status 1.

Running presubmit commit checks ...
Checking out rietveld...
Running save-description-on-failure.sh
Running push-basic.sh
Running upstream.sh
Running submit-from-new-dir.sh
Running abandon.sh
Running submodule-merge-test.sh
Running upload-local-tracking-branch.sh
Running hooks.sh
Running post-dcommit-hook-test.sh
Running upload-stale.sh
Running patch.sh
Running basic.sh

** Presubmit ERRORS **
Pylint (81 files) (33.46s) failed
************* Module trychange
E1123:464,17:_SendChangeHTTP: Passing unexpected keyword argument 'proxies' in
function call


Presubmit checks took 107.0s to calculate.

[Raphael Kubo da Costa (rakuco), 2014-01-28 09:04:52]

Duh. So urllib2.urlopen() doesn't take the `proxies' argument that
urllib.urlopen() does; given that its built-in proxy handling is more
intelligent, maybe we could get rid of --proxy altogether? This is implemented
in patch v2.

[commit-bot: I haz the power, 2014-01-30 09:18:15]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/raphael.kubo.da.costa@intel.com/133933...

[commit-bot: I haz the power, 2014-01-30 09:20:45]

Change committed as 247914

[commit-bot: I haz the power, 2014-01-30 09:21:13]

CQ bit was unchecked on CL. Ignoring.