improve rake tasks

- fail fast (sh > system)
- be consistent
improve loader error message
sh doesn't work for useful return values
improve readability of to_s3 script
fix system call
include self, to def mself.to_s3

Attempt to fix strange travis error
Stop a child processes leak.

When the test runner fails, we would not clean up
child processes. So we now ensure to kill the server
after test runs. Also, as threads + IO give us all
the concurrency we need, forking has been replaced
by a thread.

Since we don't fork, we are no longer susceptible  to
orphaned child processes.
use unusual test server port, and allow it to be configured
add support for loading ember-data
Overwrite Ember.assert to ensure test failure
Merge pull request #19 from teddyzeenny/ember-assert

Overwrite Ember.assert to ensure test failure
Add expectAssertion method to test uncatchable assertions
Merge pull request #20 from teddyzeenny/expect-assertion

Add expectAssertion method to test uncatchable assertions
Include jQuery to ember-dev
Merge pull request #21 from tricknotes/include-jquery

Include jQuery to ember-dev
ok only takes 2 arguments, the 3rd msg argument was being lost
Bump default jQuery version to 1.10.2
Merge pull request #23 from tricknotes/bump-default-jquery-version

Bump default jQuery version to 1.10.2
Use the full Ember.VERSION value to bump_version.
Merge pull request #25 from rjackson/handle_multilevel_version_numbers

Use the full Ember.VERSION value to bump_version.