big refactor and enhancement (untested)

enhancing purity to make it possible to fully unit test it, and allow
local test apps be able to run with the purity server core on the client
side too for better integration testing.
continued big refactor and enhancements

this has now been manually tested with the stopwatch example and works
when running locally with and without purity however the darteditor
build seems to be broken so I can't test running as a client server app
yet.
fix client side bug

Purity client core expects a Stream<String> not a Stream<MessageEvent>
partial README re-write

to tired to finish it tonight will finish tomorrow.
readme rewrite continued
continue refactor and enhancements

continue refactor and enhancements
add drone.io status badge
minor adjustments
fix garbage collection bug
fall back to simplistic test server view

figuring out how to generate angular components programmatically is
roving tricky, so Im implementing a simple view for now jus so I can
move forward with other things.
test server view - scroll to latest message
add a unit test and more refactorings
fix model equality comparer

overriding == should always first check that the "other" is a relevant type for comparing too first
Rename Purity_client.dart to purity_client.dart
test server close all streams on test tearDown

attempt to fix issue with drone.io test failure due to time out
cancel remaining timers on close

when the session closes it should not keep attempting to send garbage
collection transmissions down a stream which has been closed.
readme updated
Merge pull request #1 from 0xor1/big-refactor-and-enhancement

Big refactor and enhancement