Links in copyright file no longer point to license exceptions

[Bob W. Hogg]

/usr/share/doc/libjs-extjs/copyright states that various exceptions to GPLv3 are available for this package. However, the links it includes no longer point to any license exceptions, but rather straight to sencha's homepage.

     There are several FLOSS exceptions available for use with this release for
     open source applications that are distributed under a license other than the
     GPL.
     * Open Source License Exception for Applications
      http://extjs.com/products/floss-exception.php
     * Open Source License Exception for Development
     http://extjs.com/products/ux-exception.php

The copyright file should IMO reproduce the original text of these in their entirety (assuming they do actually apply to the version of ext.js used in 14.04) or should remove any references to them if they are no longer valid for some reason.

---------------

Description: Ubuntu 14.04.2 LTS
Release: 14.04

libjs-extjs:
  Installed: 3.4.0+dfsg1-1
  Candidate: 3.4.0+dfsg1-1
  Version table:
 *** 3.4.0+dfsg1-1 0
        500 http://mirror.csclub.uwaterloo.ca/ubuntu/ trusty/universe amd64 Packages
        100 /var/lib/dpkg/status