[css-transforms] Use <position> for perspective-origin. Fix transform-origin grammar (bug 26588). Add a couple of issues.

Author: smfr

css-transforms/ChangeLog

@@ -1,3 +1,8 @@
+2015-8-19 Simon Fraser <simon.fraser@apple.com>
+    https://www.w3.org/Bugs/Public/show_bug.cgi?id=26588: fix grammar for transform-origin.
+    https://lists.w3.org/Archives/Public/www-style/2015Apr/0094.html: update perspective-origin to use <position>, and fix the definition list.
+    Add a couple of issues from Bugzilla and www-style.
+
 2015-7-15 Simon Fraser <simon.fraser@apple.com>
     Move images into an images folder.