Bug 1070731 - [sms] unit test refactoring for new version chai.assert api

test_agent used very old version chai library version=0.5.3
in the current version=1.9.1 deepEqual take prototype into consideration

apps/sms/test/unit/localization_helper_test.js - plain structure
If chenge only assertChange then newer chai:
  test for onL10nReady - OK
  test for onTimeFormatChange - FAIL
Different reaction on function!! 
[sms-test/unit/localization_helper_test.js] localizes date & time onL10nReady >
    [sms-test/unit/localization_helper_test.js] ignores if date or format are unavailable ‣
    [sms-test/unit/localization_helper_test.js] correctly formats node content ‣
    [sms-test/unit/localization_helper_test.js] correctly formats node l10n attributes ‣
[sms-test/unit/localization_helper_test.js] localizes date & time onTimeFormatChange >
    [sms-test/unit/localization_helper_test.js] ignores if date or format are unavailable ‣
    [sms-test/unit/localization_helper_test.js] correctly formats node content ‣

    Error: Date-only elements should not be updated: expected '"2014-09-30T13:42:18.310Z"format12' to equal ''
        at chaiAssert (app://sms.gaiamobile.org/common/test/helper.js:48:1)
        at equal (app://sms.gaiamobile.org/common/vendor/chai/chai.js:2437:1)
        at assertChange (app://sms.gaiamobile.org/test/unit/localization_helper_test.js:124:13)
        at (anonymous) (app://sms.gaiamobile.org/test/unit/localization_helper_test.js:149:1)
        at wrapper (app://sms.gaiamobile.org/common/test/mocha_generators.js:62:19)

    [sms-test/unit/localization_helper_test.js] correctly formats node l10n attributes 
Error: Date-only elements should not be updated: expected { Object (data, date) } to deeply equal { data: 'custom' }
    at chaiAssert (app://sms.gaiamobile.org/common/test/helper.js:48:1)
    at assertEql (app://sms.gaiamobile.org/common/vendor/chai/chai.js:1428:1)
    at (anonymous) (app://sms.gaiamobile.org/common/vendor/chai/chai.js:3627:18)
    at deepEqual (app://sms.gaiamobile.org/common/vendor/chai/chai.js:2523:5)
    at assertChange (app://sms.gaiamobile.org/test/unit/localization_helper_test.js:163:13)
    at (anonymous) (app://sms.gaiamobile.org/test/unit/localization_helper_test.js:192:1)
    at wrapper (app://sms.gaiamobile.org/common/test/mocha_generators.js:62:19)