Align correctly tabs.

Add API for showing toast notifications, using the system behaviour.
Expose interface for users to handle raw and toast notifications by js callbacks.
This way they can handle notifications differently than the system

If user want to open new channel they have to have the option to close the current one.
Update the error text.
Remove the channel field as it is not necessary.

It appears that MPNS opens only one channel per application and defines it by name.
Sometimes the channeluriupdate is called with delay and it looks like the channel has no Uri. Handle this by adding urichangedcallback js function.
Added js error callback to handle errors.
Added error to notify the user if they try to open new channel but already have opened one as this is throwing argument exception.
Extract the js function execution in separate method as it is reused.

Adding TryCast method improves readability and decreases the code nesting.

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