Fix Null pointer expection when Phone is in low memory

ThumbnailManager tries to get the bitmap and throws null
pointer exception when cache is null.

Change-Id: Iba557e5d9aa6c0990ee47c79788c4c1c55121c63
CRs-Fixed: 539366
Fix the send button disappearance after selecting the forward recipient

During onRestart method the bottom panel is hidden for the
ComposeMessageActivity.

Change-Id: Ica243945237003a37d0832c556e45c5b43dd0497
CRs-Fixed: 568266
The draft still exists after forwarding mms to the same sender

Forward message will be saved as draft before sent, and it will reload
this draft after come back to the current thread.

Do not load the draft for the same recipient address when forwarding
mms.

Change-Id: I2cc873a9bcbdf0e6481391a0237eb1d19f40d137
CRs-Fixed: 568255
Display message type properly for MMS and SMS

When a message is showed details, android will search it in mms
& sms list according to its message id. But sometime the message
id of sms message is the same with that of mms message and the
special mms message is before the sms message in mms & sms list,
so the sms is displayed as mms.

To fix this bug, message type is to be checked at the same time.

Change-Id: I35f8586bf97a553a53424adb2458a8c7fd9ba0e9
CRs-Fixed: 568258
Resize the image in background

Decoding and resizing of the image is done in
Adapter-getView method which runs in the main
thread. As a result edit screen resumes after
few seconds, mean time if user flings on that
activity it leads to ANR.

From getView method, adopt lazy loading - spawn
the thread which will decode and resize the
image, upon receiving the requested resized-image
set the image to the view.

Change-Id: I7500afc2fcc4fd7bed8f256d19cbc22ee9baeda0
CRs-Fixed: 550421