added error.js for custom errors

Conflicts:

	routes/account.js
	routes/index.js
	routes/password.js
	routes/sign.js
	test/account_tests.js
many changes to client module, started integration tests

Conflicts:

	gherkin.js
	lib/client.js
	test/account_reset_token_tests.js
	test/bundle_tests.js
	test/key_fetch_token_tests.js
	test/recovery_method_tests.js
	test/srp_session_tests.js
made integration.js slightly less ghetto
work around mysql in Account.del test
Fixing some require paths. Moving error.js into lib.
Fix model import in api.js
Merge pull request #2 from mozilla/merge-2013-07-31

Merge 2013 07 31