3rdparty/BUILD: split up into package dirs - part 11

RB_ID=539094
TBR=true
util-stats: Deprecated old StatsReceiver API, improved java compatibility

Problem

StatsReceiver#time{,Future} are unfriendly to java, and make more sense on Stat than on StatsReceiver.

Solution

Deprecate StatsReceiver#time{,Future} and provide explicit java and scala helpers to time and timeFuture.

Result

StatsReceiver is easier to use from java, and has a cleaner API.

RB_ID=516893
Bump all sbt projects (util, ostrich, finagle, twitter-server)

Problem

After looking at the finagle changelog, I discovered that we already had
entries for finagle 6.23.0 and more for the current version.
The previous version bump was then incorrect, the version needs to be
greater than 6.23.0.

Solution

Bump the minor version of finagle, and for consistency I did the same
thing for all the other related projects.
Close the current section of the finagle changelog and name it "6.24.0".

RB_ID=540180
util-cache: add LoadingFutureCacheTest

RB_ID=538281
util-cache: add LazilyEvictingCache tests and rm dead code in FutureCache

RB_ID=538027