Add support for unix socket of memcached

Review Request #7940 — Created Feb. 3, 2016 and submitted — Latest diff uploaded

Information

Review Board
release-2.5.x

Reviewers

"python-memcached" supports unix sockets with "unix:/path/to/socket".
So the cache_stats should support that scheme, too.

Started memcached with:
* memcached -l 127.0.0.1 -p 11211
* memcached -s /tmp/socket

Tried path "unix:/tmp/socket" and "localhost:11211" as the memcached
connection in admin.

"Cache Stats" in admin dashboard works correct and caching of diffs in reviews, too.