Updated event names for the callback so existing sample code works with both android and amazon-fireos

JIRA: https://issues.labcollab.net/browse/ATLS-1064

cr https://cr.amazon.com/r/2292352/

Config options are persisted now. When app is forced stopped, we read config options from sharedPreferences.
Also, fixes error message not being shown properly.

Fixed couple of issues - 1. permission denied when launching the app from notification. 2. Message is not downloaded when resumed after hitting hoem button.

Added server script and readme for Amazon Device Messaging.

Update README.md

Added instrucction to Android manual installation

Fixed quotes unescaping for non string values

fix e.regid in README

json key should be surrounded by quotation

Update plugin.xml

adds android.permission.VIBRATE needed for android 2.3.x

#85 - new approach

We should always send a notification this is better than never sending one

We can rely on the the other activity functions setting foreground to be true

#85 No notifications in android when the app is closed

Allow the plugin to know when the app is no longer in foreground so that it may receive push notifications

Added clobbers for PushNotification

JSON fix

Callback now invoked