Quiet tests

This disables the console logger on the  test backend so that tests
which pass do not spew their output. As nose captures logging already,
you'll only see the relevant logging for tests which fail, making it a
lot easier to find what is wrong.
No more sleeping in the webhooks_tests
added a test on html entities
Merge pull request #148 from zoni/quiettests

Quiet tests
Make execute_and_send() a self-contained method

This makes callback_message a bit less of a huge monolithic method and
will also make it easier to write unit tests against execute_and_send in
the future.
Add tests for execute_and_send()
Allow botcmd's to yield values

botcmd's which use yield will have each yielded value be sent to the
person who executed the command. This allows long-running commands to
use yield to keep a user informed of what is going on.
Also test HTML templating when testing execute_and_send()
Link build status image to the builds page on travis-ci.org
Readme: Mention Sentry integration in feature list
Readme: Various style fixes and text adjustments
Readme: Fix reStructuredText markup

Sleepy me somehow managed to confuse Markdown and reStructuredText
markup with each other. Yes, I'm a dummy. :)
Further update the readme

Mainly formatting changes, update/change feature list, installation
instructions and add an example of a hello world plugin.
Merge pull request #150 from zoni/yieldcommands

Allow botcmd's to use yield
Merge pull request #151 from zoni/readme

Readme update
Update README.rst

Corrected the blurb
Update README.rst

Updated jabberbot statement, it really too far from it now
Mention other projects we make heavy use of, not only yapsy

It seems only fair to list them all, as yapsy is only one of a
handful of libraries that make Err as feature-rich as it is today.
Clean up config-template.py

Except for making BOT_ASYNC True by default (I believe it is no
longer experimental, I have been running it without issue in
production for over 6 months), this doesn't change any
configuration items. It only orders and groups items in a way that
makes the most sense, and changes the commenting around options to
be mostly consistent.
Fix a whitespace issue in config-template