BEEM - Android XMPP

There is currently no(!) single XMPP client for Android that implements message receipts. Still knowing that the message I sent actually arrives at the recipients phone is very important to ensure reliability in the conversation. It's part of what makes Skype, WhatsApp and text messaging/SMS strong on cell phones. Hence I'd like to suggest to make beem the first Android client to support it. In terms of user interface I suggest that a green check mark is shown once the delivery receipt has been received. This can be shown in the place where a pending icon (see issue 397) was shown before transmission to the server.

If logs are written the id's of the messages and the receipt status should be stored as well. This will enable beem to read the log, show the receive-status of the old messages and, if receiving a receipt for an old message, to add the checkmark/receive-flag to it as well.