During development, it is fairly common to cycle between writing code and
testing that code. Generally the testing happens within the test suite, but
frequently it is more convenient to test things by hand when tracking down
a bug, or when doing some exploratory coding. In many situations, however,
this becomes inconvenient - for instance, in a REPL, or in a stateful web
application, restarting from the beginning after every code change can get
pretty tedious. This module allows you to reload your application classes
on the fly, so that the code/test cycle becomes a lot easier.
