PHPC-799: Add THIRD_PARTY_NOTICES file

This references the THIRD_PARTY_NOTICES files from libbson and libmongoc, which were added in CDRIVER-1557.

Author: jmikola

THIRD_PARTY_NOTICES

@@ -0,0 +1,78 @@
+The MongoDB PHP Driver uses third-party code distributed under different licenses.
+
+The MongoDB PHP Driver uses libbson and libmongoc, which also use third-party
+code distributed under difference licenses. See src/libbson/THIRD_PARTY_NOTICES
+and src/libmongoc/THIRD_PARTY_NOTICES for additional information.
+
+
+License notice for php_array_api.h
+-------------------------------------------------------------------------------
+
+-------------------------------------------------------------------- 
+                  The PHP License, version 3.01
+Copyright (c) 1999 - 2014 The PHP Group. All rights reserved.
+-------------------------------------------------------------------- 
+
+Redistribution and use in source and binary forms, with or without
+modification, is permitted provided that the following conditions
+are met:
+
+  1. Redistributions of source code must retain the above copyright
+     notice, this list of conditions and the following disclaimer.
+ 
+  2. Redistributions in binary form must reproduce the above copyright
+     notice, this list of conditions and the following disclaimer in
+     the documentation and/or other materials provided with the
+     distribution.
+ 
+  3. The name "PHP" must not be used to endorse or promote products
+     derived from this software without prior written permission. For
+     written permission, please contact [email protected].
+  
+  4. Products derived from this software may not be called "PHP", nor
+     may "PHP" appear in their name, without prior written permission
+     from [email protected].  You may indicate that your software works in
+     conjunction with PHP by saying "Foo for PHP" instead of calling
+     it "PHP Foo" or "phpfoo"
+ 
+  5. The PHP Group may publish revised and/or new versions of the
+     license from time to time. Each version will be given a
+     distinguishing version number.
+     Once covered code has been published under a particular version
+     of the license, you may always continue to use it under the terms
+     of that version. You may also choose to use such covered code
+     under the terms of any subsequent version of the license
+     published by the PHP Group. No one other than the PHP Group has
+     the right to modify the terms applicable to covered code created
+     under this License.
+
+  6. Redistributions of any form whatsoever must retain the following
+     acknowledgment:
+     "This product includes PHP software, freely available from
+     <http://www.php.net/software/>".
+
+THIS SOFTWARE IS PROVIDED BY THE PHP DEVELOPMENT TEAM ``AS IS'' AND 
+ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 
+PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE PHP
+DEVELOPMENT TEAM OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+OF THE POSSIBILITY OF SUCH DAMAGE.
+
+-------------------------------------------------------------------- 
+
+This software consists of voluntary contributions made by many
+individuals on behalf of the PHP Group.
+
+The PHP Group can be contacted via Email at [email protected].
+
+For more information on the PHP Group and the PHP project, 
+please see <http://www.php.net>.
+
+PHP includes the Zend Engine, freely available at
+<http://www.zend.com>.