Fix LICENCE file name and add AUTHORS file.

Change-Id: I70fa050890346a72f8a02508d32372d9e6dc52c9
Reviewed-on: http://gerrit.dmdirc.com/2650
Reviewed-by: Chris Smith <chris@dmdirc.com>
Automatic-Compile: DMDirc Build Manager

AUTHORS

@@ -0,0 +1,6 @@
+# This is the official list of DMDirc Developers for copyright purposes.
+Chris Smith <chris@dmdirc.com>
+Google Inc.
+Greg Holmes <greg@dmdirc.com>
+Shane McCormack <shane@dmdirc.com>
+Simon Mott <simon@dmdirc.com>