Add ECL license info to source code

[dstillman]

We need to add an ECL license file to the root directory plus a header with copyright and license info on all files. License available at ​http://www.opensource.org/licenses/ecl1.php.

Source code files should contain the follow text:

Copyright (c) 2006  Center for History and New Media,
                    George Mason University, Fairfax, Virginia
                    http://chnm.gmu.edu
 
Licensed under the Educational Community License, Version 1.0 (the "License"); 
you may not use this file except in compliance with the License. 
You should have received a copy of the License along with this program.
You may also obtain a copy of the License at 
 
http://www.opensource.org/licenses/ecl1.php 
 
Unless required by applicable law or agreed to in writing, software 
distributed under the License is distributed on an "AS IS" BASIS, 
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
See the License for the specific language governing permissions and 
limitations under the License.

[david]

(In [411]) Addresses #63, Add GPL license info to source code.

License file added.
Header added to David's interface files -- add header to your own files.

[dstillman]

Updating to reflect ECL license rather than GPL

[dstillman]

(In [454]) Addresses #63, Add ECL license info to source code

Replaced GPL license.txt with ECL

[dstillman]

(In [571]) Addresses #63, Add ECL license info to source code

Stripped GPL text and removed ECL license for now -- leaving in copyright notice where it exists

[dstillman]

(In [743]) Closes #63, Add ECL license info to source code

Added on all non-trivial files -- be sure to copy over XML or JS version as appropriate for new files