SI-6258 Reject partial funs with undefined param types

This regressed with virtpatmat.

With -Xoldpatmat, pattern matching anonymous functions with
an expected type of PartialFunction[A, B] are translated to
a Function tree, and typed by typedFunction, which issues an
error of the parameter types are not fully defined.

This commit adds the same check to MatchFunTyper.

It doesn't plug the hole in RefChecks#validateVariance (which is
reminiscent of SI-3577.) Seems to me that in general one should handle:
  a) both BoundedWildcardType and WildcardType
     when in a place that can be called during inference, or
  b) neither otherwise
Merge pull request #1260 from jsuereth/issue/5031

Issue/5031
removes Type.isConcrete

This method was no longer used anywhere, except for a place where it wasn't
really necessary.

Its implementation is non-trivial, and I have doubts about it, so I propose
to remove it altogether instead of living with some dubious code necessary
for some dubious matter.
Merge pull request #1266 from scalamacros/topic/removes-isconcrete

removes Type.isConcrete
removes isLocatable from the public API

Hard to come up with a good name, would need extensive documentation
to justify its purpose => no go. If necessary we can always reintroduce
it later in 2.10.1.
Merge pull request #1168 from retronym/ticket/6258-2

SI-6258 Reject partial funs with undefined param types
SI-6246 deprecated apis for core class tags

Aliases ClassTag.XXX to Manifest.XXX to reuse already existing
implementations of deprecated APIs.
fixes Manifest.Nothing and Manifest.Null

Also introduces an important change to Manifest.Nothing and Manifest.Null.
Previously their `erasure` was equal to classOf[Object]. Now it's correctly
set to classOf[scala.runtime.Nothing$] and classOf[scala.runtime.Null$]
correspondingly.

See a discussion here:
https://groups.google.com/forum/#!topic/scala-internals/Y0ALGo7QPqE
Merge pull request #1267 from scalamacros/ticket/6246

fixes for class tags and manifests
SI-6318 fixes ClassTag.unapply for primitives

ClassTag.unapply now has overloads for primitive value classes
so that it can preserve boxiness when performing subtyping tests.

First I wanted to annotate ClassTag.unapply with a ClassTag itself,
i.e. to transform its signature from "def unapply(x: Any): Option[T]"
to "def unapply[U: ClassTag](x: U): Option[T]".

But then virtpatmat_typetag.scala exhibited a nasty problem.
When pattern matching with this unapply, patmat first infers U as something
and then tries to pattern match against this inferred type. And if U gets
inferred as an abstract type itself, bad things happen:
warning: The outer reference in this type test cannot be checked at run time.

That's why I decided to drop the ClassTag idea and go with 9 extra overloads.
Not very beautiful, but definitely robust.
Merge pull request #1268 from scalamacros/topic/removes-islocatable

removes isLocatable from the public API
Merge pull request #1265 from scalamacros/ticket/6318

SI-6318 fixes ClassTag.unapply for primitives
Fix for SI-6333 - Try throws from combinators.

* Added  more comprehensive tests to Try.
* Delineated what methods do and don't catch exceptions in docs.
* Fixed combinator methods that should catch exceptions.
Minor code style alterations and performance fixes.

Specifically, avoid reinstantiating an immutable object to alter the type parameter *IF*
that type parameter has nothing to do with the contents of the object.