Update credits and bump to version 1.4.1

Update files to 1.4 (#149)

* Update README and screenshots

* Update version number in about.lua

Release 1.3.0

Release 1.2.0

Update contributors & version (1.1.4)

Update about.lua

Fix re-open of message view

After sending a message from drafts and closed the formspec, at next  call.

1.1.x (#68)

* Fix close button which makes the formspec blinking (#65)

* Fix header click + use them as sorting (#66)

* Abort checking messages when clicking on a header row (indexing a nil value)

* Use headers clicks to change sorting

* Fix oversized selected number #67  (#67)

* about.lua to 1.1.1

Update README

Update HUD in mail.mark_read