Automattic/msm-sitemap — pull request #49 by pcrumm (2013-12-20 22:27:37+00:00)
Title: Ping search engines on sitemap update

When the sitemap is changing, ping Google and Bing's endpoints to allow them to update their indexes. A few aspects of note:
* Yahoo! and Bing now share an index, and subsequently share a ping endpoint as well.
* Both Google and Bing recommend pinging no more than once an hour