Update changelog for 3.0.0+really3.0.0-3 release

debian/changelog

+php-xml-htmlsax3 (3.0.0+really3.0.0-3) unstable; urgency=medium
+
+  [ David Prévot ]
+  * Document upstream VCS
+  * Update Standards-Version to 3.9.7
+  * Rebuild with latest pkg-php-tools for the PHP 7.0 transition
+
+  [ Daniel O'Connor ]
+  * Drop PHP4 reference syntax
+
+ -- David Prévot <taffit@debian.org>  Wed, 02 Mar 2016 20:53:45 -0400
+
 php-xml-htmlsax3 (3.0.0+really3.0.0-2) unstable; urgency=medium
 
   * Remove doc as advised in pkg-php-tools(1) (Closes: #743116)