[split] better error message in ipToInt

RB_ID=245235
[split] Add functionality to AsyncSemaphore for executing functions as permits become available

RB_ID=242223
[split] util, finagle, scrooge: Remove deprecated withSources from Build.scala

RB_ID=248091
[split] UpdatableVar: fine-grained locking to prevent deadlocks.

Deadlocks may happen because observation and updating with respect to
derived Vars happen in the opposite order, and some operations (such
as observeUntil) manipulate state synchronously with updates.

A simple example:

	val a = Var(333)
	val b = Var(a)
	val c = b flatMap identity

	thread 1:
		b.observeUntil(_==333)
	thread 2:
		a() = 333

here, thread 1 is racing with thread 2: t1 may observe, then
synchronously close(); however in the meantime t2 may try to lock a,
then, b, then, c whereas t1 already holds the lock for b while it's
trying to close a. This leaves us in a situation where t2 holds the
lock on a, t1 holds the lock on b while t2 is trying to get the lock
for b, and vice-versa.

Another fix for this would be to have observeUntil participate in
future scheduling, but that seems like a hack.

RB_ID=245305
[split] Move com.twitter.servo.util.Memoize into util-core.

RB_ID=233169
TBR=true
NO-QUEUE=true
[split] bump util to 6.10.1-SNAPSHOT

RB_ID=251907
TBR=true
[split] util-core: Alias juc.CountDownLatch used in Memoize

Missed a compiler warning about j.u.c.CountDownLatch conflicting
with c.t.u.CountDownLatch.

RB_ID=252019
NO-QUEUE=true
[split] ServerSets2: First version

RB_ID=241349
[split] Revert "ServerSets2: First version"

RB_ID=252927
TBR=true
NO-QUEUE=true
[split] ServerSet2: First version

RB_ID=241349
[split] Events: discrete-time values

/**
* Events are instantaneous values, defined only at particular
* instants in time (cf. [[com.twitter.util.Var Vars]], which are
* defined at all times). It is possible to view Events as the
* discrete counterpart to [[com.twitter.util.Var Var]]'s continuous
* nature.
*
* Events are observed by subscribing to them; subscribers are
* [[com.twitter.util.Subject Subjects]] to which the Event's values
* are emitted.
*/

RB_ID=242077
[split] Fix finagle-serversets dependencies discrepancy

RB_ID=257731
[split] ServerSet2: weight/priority vectors

RB_ID=253793
[split] finagle, util: s/setValue(())/setDone()/g

RB_ID=260251
[split] Future: utilities for composing side effects

Future.followedBy: sequencing side effects;
Future.sleep: equivalent to Thread.sleep() for Futures.

RB_ID=260533
[split] Bridged thread pool scheduler

RB_ID=252615
[split] util-logging: Gets correct method and class name in c.t.u.LogRecord

RB_ID=248087
[split] Future.followedBy->Future.before

RB_ID=263637
[split] Spool improvements: * Fix forcing issues with *::  ... there were two problems:   1) `implicit def syntax[A]` was forcing its lazy parameter   2) the `cons` method used in Syntax[A] was also forcing the lazy parameter * Add an optionally-imported seqToScala implicit to add .toScala to Seq[A]

RB_ID=263489
[split] Birdcage: Bump guava to 15.0 - Bump guava to 15.0 - Synchronize bijection versions, and comment on the twitter/public bijection split

Corresponds to science review https://reviewboard.twitter.biz/r/263149/

RB_ID=263101