The original AJAX Control Toolkit license prohibited the name of the
CodePlex Foundation from being used to endorse/promote derived products.
We need to preserve this requirement. This was already done in the .js
header blocks, and should have been done in LICENSE.txt in a7c96c56 but
was missed.
Original discussion in #10. Permission for the license change was given
by all existing contributors in #58.
The license text will be provided on the website, etc., and it seems
strange to list no copyright date newer than the original CodePlex
copyright from the AJAX Control Toolkit. Add a blanket copyright
statement for contributions to the OpenSeadragon project, stating that
copyright is held by the authors of each contribution. This blanket
statement is not intended to preclude individual contributors from
attaching their own copyright statements to their modifications.
All OpenSeadragon contributors have granted their permission for this
relicensing in #58.
Drop copyright statements for Ian Gilman and Christopher Thatcher as
they requested in #10.
Revert CodePlex Foundation copyright date to 2009 pursuant to discussion
in #10.
