More info about replication.

This adds info about diskless replication, and safety of runnign a
mastesr with persistence turned off.
Merge remote-tracking branch 'origin/master'
Added EC2 specific info to admin page.
Latency page improved.
Huge pages section removed since they are evil anyway.
this -> these.
In computing a single slash makes difference.
Another slash.
Added C++/Boost Asio client
Merge pull request #452 from nekipelov/master

Added C++/Boost Asio client
Document newly integrated BitOps library
Merge pull request #455 from badboy/document-bitop

Document newly integrated BitOps library
Latency: specify that intrinsic latency must be checked on the server.
Merge branch 'master' of github.com:/antirez/redis-doc
Merge branch 'master' of github.com:antirez/redis-doc into copyedits

Conflicts:
	topics/latency.md