Version 1.2.3 fixes a force close reported and fixed by quincunx

Version 1.2.2 Adds the countdown notification and reknock feature. Also fixes a few outstanding bugs, including a longstanding occasional crash caused by Juicessh.

Fixes a very rare Null reference crash, also attempts to fix building on F-Droid

Version 1.2 adds the new source IP prompt, NFC token support, and an option to launch OpenVPN for Android on a successful knock. Also adds support for multiple hashing types and nat-local support.

Version 1.1 adds Legacy mode, the option to prompt for key when sending knock, tcp and http mode, random server ports, and adds a send knock button instead of requiring a long tap to send knocks. Fixes include squashing a visual bug, fixing a couple potential crashes on very new Android versions, and preventing the ssh client from running if the knock failed.

Version 1.1 Beta 1 adds Legacy mode, the option to prompt for key when sending knock, tcp and http mode, and adds a send knock button instead of requiring a long tap to send knocks. Beta 2 Fixes a visual bug and prevents the ssh client from running if the knock failed.

This release fixes a bug with saving a config containing a server command. It also moves to using the zxing library built in to the apk rather than an external app, and allows for prompting for the password when sending the knock rather than saving it in the database.

V1.0.1 Fixes a permissions related crash that can occur if Juicessh is installed after Fwknop2

This is the final release of v1.0.

Adds base64 validation as suggested by Michael Rash.