DownloadProvider: Transfer speeds in notification

Change-Id: Ic7efcdfe7a329946f3b63c331064ac2f16faafeb
DownloadProvider: Normal notification for singles

This builds upon the previous DownloadNotifier, but changes
the notification style when downloading single files by
removing the big view.

Change-Id: I06d2b555bb51613661ccb50df3b7bc59439b2252
DownloadProvider: Standardize notifications

Standardize play store and browser download notifications
Image: http://i.imgur.com/w3VaRUK.png

Change-Id: Ibadcca3725b4adb330a5670414ac8f89790448b8
[2/2] DownloadProvider: DownloadManager: add support pause/resume/stop notifications

User can manually pause current download and resume to continue download remaining data of the file.
add a progressbar to show download progress. (only legacy View)
add pause/resume/stop/retry into notifications
add remaining time into notifications

Conflicts:
	res/values/custom_strings.xml
	src/com/android/providers/downloads/DownloadNotifier.java

Change-Id: I7c2c6043bd6e26c4d4b0c74265f87629967302a0