Handling Exceptions

Updated mailsnake.py to handle urllib and simplejson exceptions. Also,
it now handles all MailChimp API exceptions
(http://apidocs.mailchimp.com/api/1.3/exceptions.field.php)
MailSnake 1.3.1

I'm attempting to take over maintenance of @leftium's mailsnake repo,
it appears to be abandoned.

* Updated the README file
* Added exceptions (very verbose, I may add)
* Library is now on pip

```pip install mailsnake```

* Updated credits
* More verbose simplejson/json importing
* Sort of a PEP8 cleanup
* Cleaned up the init/call methods to take None for params and THEN set
the variable according to if it was passed (18, 25; 33, 35
[mailsnake.py])
README was in the wrong place. :P
Prepping for MailChimp STS support, couple fixes, version bump
if the result of API call is just 'true' or 'false' the line if 'error' in rsp and 'code' in rsp: will fail
don't look for errors in string or boolean responses
forgot to erase previous change..
Merge pull request #1 from vlinhart/patch-1

Return MailChimp response instead of raising an error if response isn't a dict
Bump version
Default parameters shouldn't overwrite the call's explicitly defined parameters.
Merge pull request #11 from StephenWeber/patch-1

Change order of dict update in call()
There's no .code in URLError
Merge pull request #2 from starenka/patch-1

There's no .code in URLError
1.3.4 release

* Include a README.rst for pip
* Bump version

Fixes:
* URLError has no attribute code
1.3.4 release

* Fixed rst error
Assume int responses are not errors

An update to 43642a6cd8.  The campaignSegmentTest call returns
an integer (number of subscribers in a segment).

This should probably be 'isinstance(rsp, dict)' but I did not
have an opportunity to try that yet.
Merge pull request #3 from mediacloud/master

Assume int responses aren't errors
1.3.5

Assume ints aren't errors
extend mailsnake to work with the sts and export apis
update documentation