mesa: Add "OR COPYRIGHT HOLDERS" to license text disclaiming liability.

This brings the license text in line with the MIT License as published
on the Open Source Initiative website:

http://opensource.org/licenses/mit-license.php

Generated automatically be the following shell command:
$ git grep 'THE AUTHORS BE LIABLE' | sed 's/:.*$//g' | xargs -I '{}' \
  sed -i 's/THE AUTHORS/THE AUTHORS OR COPYRIGHT HOLDERS/' {}

This introduces some wrapping issues, to be fixed in the next commit.

Reviewed-by: Brian Paul <brianp@vmware.com>

docs/license.html

@@ -75,7 +75,7 @@ in all copies or substantial portions of the Software.
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
-THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 </pre>