Add `raise_send_errors` flag to the base `Client`.
This indicates whether the client will handle or raise any exceptions encountered while sending to Sentry.
* The default value (False) matches the current behaviour in which the client handles the error.
* Setting this argument to True allows for the calling application to handle the exception and
  thus determine its own retry and backoff strategies.
If a SentryHandler's client is set with `raise_send_errors = True`, do not handle the errors in `SentryHandler.emit`.
Truncate frames a maximum of 50
Added a test on the url encoded strings.
Added a test on the url encoded strings (thanks to @simonpercivall)
Reverting previous changes.
Remove zeromq transport as it's invalid
Check app.version because Markdown does this
map instead of list comprehension because faster
Merge pull request #416 from mattrobenolt/master

Support app.version as a way of getting the version
Get ready for Django 1.7
Stop using mirrors
Don't catch *all* exceptions
We actually do a lot of json encoding and this is faster
Isolate the KeyError
We don't really need to expose that globally
Fix mutable kwargs
We shouldn't swallow the entire json error

This random string being returned then goes along and gets sent to Sentry
which then ultimately gets discarded since it's invalid
Fix docstringt
4.0.4