updating userAgent parsing logic.
Merge pull request #35 from apigee/USERGRID-2556

updating userAgent parsing logic.
updating ios push notification sample
updating adroid push sample from https://github.com/mdobson/phonegap-apigee-android-push
updated iOS readme
Merge branch 'USERGRID-2461' of github.com:apigee/apigee-javascript-sdk into USERGRID-2461