Fixes behavior on hangups and aborts

The existing behavior on hangups and aborts disregarded the parameters
passed in via options, and failed at a number smaller than maxRetries.
This is counter intuitive, undocumented, and not modifiable from the
external API.

This pull request defaults maxHangups and maxAborts to maxRetries and
changes the underlying code to actually use those values rather than
hard coded values.
Merge pull request #15 from Ink/master

Fixes behavior on hangups and aborts