SI-6976 Fix value class separate compilation crasher.

We can't guarantee that the owner of the value class
is initialized, and if it isn't, the search for the
companion module will turn up bubkis.

This is a localized fix, but I'd be suprised if there
weren't other places that suffered from the same problem.

Wouldn't it be nicer to have something like:

    // doesn't force info
    sym.raw.info
    sym.raw.companionModule

    // forces info
    sym.info
    sym.companionModule
Forgot to cherry-pick the .check file
There is no "letters" method in this branch
SI-4976 Scaladoc: Add a source link to package objects
Merge branch '2.10.x'

Conflicts:
	src/compiler/scala/tools/nsc/doc/Settings.scala
	src/compiler/scala/tools/nsc/interpreter/CompletionOutput.scala
	src/compiler/scala/tools/nsc/matching/Patterns.scala
	src/compiler/scala/tools/nsc/transform/UnCurry.scala
	src/compiler/scala/tools/nsc/typechecker/Infer.scala
	src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala
	src/compiler/scala/tools/nsc/typechecker/Typers.scala
	src/reflect/scala/reflect/internal/settings/MutableSettings.scala
	src/reflect/scala/reflect/runtime/Settings.scala
	src/swing/scala/swing/SwingActor.scala
	src/swing/scala/swing/SwingWorker.scala
	test/files/run/t6955.scala
align partest script with ant

don't silently pass -deprecation to scalac by default
SI-6601 Publicise derived value contstructor after pickler

Otherwise the access restrictions are not enforced under
separate compilation.

See also SI-6608.
Merge pull request #1899 from paulp/pr/extract-scaladoc

Granted scaladoc its own Global.
Merge pull request #1905 from adriaanm/ticket-6956

SI-6956 determine switchability by type, not tree
Merge commit 'refs/pull/1906/head' into wip/pr-1906

* commit 'refs/pull/1906/head': (24 commits)
  SI-6675 Test new warning under -Xoldpatmat.
  SI-6675 -Xlint arity enforcement for extractors
  SI-6905 - Switch to sneakyThrows instead of Unsafe.throwException as per new jsr166y to avoid issues with Android
  SI-6963 Deprecates -Xmigration switch
  SI-5954 Implementation restriction preventing companions in package objs
  SI-6479 Don't lift try exprs in label arguments.
  SI-6082 Conditionally expand @ann(x) to @ann(value = x)
  SI-6126 Test case for varargs of tagged primitives.
  SI-5440 Test case for exhaustiveness check
  SI-5340 Change println to log
  SI-6955 switch emission no longer foiled by type alias
  clean up synthesizePartialFunction
  rework partial function synthesis
  SI-6925 use concrete type in applyOrElse's match's selector
  SI-5189 detect unsoundness when inferring type of match
  SI-6946, SI-6924 Greatly improves IsTraversableLike docs
  SI-6555 Scaladoc's class filter shouldn't drop the last character
  Backport of SI-6846.
  Fixes SI-6521, overrides Range#head to be faster
  SI-6641 Deprecate SwingWorker
  ...

Conflicts:
	src/compiler/scala/tools/nsc/typechecker/Typers.scala
Merge pull request #1854 from pufuwozu/ticket-SI-6923

SI-6923 Context now buffers warnings as well as errors
Merge pull request #1914 from retronym/ticket/6601

SI-6601 Publicise derived value contstructor after pickler
Merge pull request #1919 from paulp/pr/fix-merge-210

Re-merge of #1906
SI-6811 Remove scala.annotation.serializable

Every usage of it has been eliminated in earlier commits,
so the source file can finally be removed, too.
SI-6811 Remove usages of scala.annotation.cloneable

The source file itself will be removed later,
because the compiler seems to need it for boot-strapping.
SI-6811 Remove deprecated constructors
SI-6811 Remove primitive widenings and /:\
SI-6811 Remove scala.collection.mutable.ConcurrentMap
SI-6811 Remove the scala.util.grammar package
SI-6811 Remove parts of scala.concurrent not needed by scala.actors