SI-7969 REPL -C columnar output

Let `ConsoleReaderHelper.printColumns` print in a vertical
orientation (similar to `ls -C`) instead of horizontally (`ls -x`).

To support the old behavior, add a property `-Dscala.repl.format=across`
where "across" is the presumptive mnemonic for `-x`.

The format property also takes value `paged` to turn on pagination,
which currently forces single-column output (as does `ls | more`)
for simplicity.
SI-7969 Refactor to trait with test

Make REPL classes testable in junit. Test the Tabulator.
Tidy up the Uncurry component of delambdafy

 - Use tree factories that accept symbols and encapsulate ValDef
   creation
 - Use `gen.mkForwarder` to handle the conditional addition of
   `: _*` for varargs functions. We don't need to predicate this
   on `etaExpandKeepsStar`; the only place that need to do that
   is EtaExpansion.
SI-7969 REPL variable columnar output

Extend column formatting to make columns only as wide as
their widest element.  This is similar to what `ls` does.

Given the longest and shortest string, which bound the
min and max column count, compute the layout for those
possible column counts, and choose the minimal row count
and minimal column count.

The junit test is under pending because it uses expecty.
(Edit: updated without expectytations.)

Example that really benefits, witness the skinny columns:

```
scala> math.

BigDecimal                     PartiallyOrdered             cosh      rint
BigInt                         Pi                           exp       round
E                              ScalaNumber                  expm1     signum
Equiv                          ScalaNumericAnyConversions   floor     sin
Fractional                     ScalaNumericConversions      hypot     sinh
IEEEremainder                  abs                          log       sqrt
Integral                       acos                         log10     tan
LowPriorityEquiv               asin                         log1p     tanh
LowPriorityOrderingImplicits   atan                         max       toDegrees
Numeric                        atan2                        min       toRadians
Ordered                        cbrt                         package   ulp
Ordering                       ceil                         pow
PartialOrdering                cos                          random

```

more
SI-7967 Account for type aliases in self-type checks

These eluded the check for "illegal inheritance; self-type does not
conform" as AliasTypeRef doesn't forward `typeOfThis`.

This commit dealiases before calling `typeOfThis`. That seems to be
the most localised change.

Without the dealias, we had:

    parent.tpe            = TypeRef(pre, sym = AliasTypeSymbol("CC"), Nil)
    parent.tpe.typeOfThis = parent.tpe.transform(sym.typeOfThis) = CC

After:

    parent.tpe.dealias            = TypeRef(pre, sym = ClassSymbol("C"), Nil)
    parent.tpe.dealias.typeOfThis = C with B
Test in quick mode for ant build

Add a target `test.suite.quick`.

Let test.quick depend only on init and quick.done,
and load the task using the quick path (with non-core deps).
SI-7872 Plug a variance exploit in refinement types

Refinement types are collapsed to a TypeTree with an original
during type checking; this was enough to evade variance validation
in refchecks.

This commit:

  - validates the original of `TypeTree`s in refchecks
  - changes VarianceValidator to recurse into:
    - the originals of `TypeTree`s
    - `TypTree` (to cover, e.g. `CompoundTypeTree` / `SelectFromTypeTree`)

It also finds an unreported variance violation in an existing
test case, variances.scala. This looks to be legitimate.
Symbol substutition must consider ClassInfoType#parents

An upcoming change to uncurry, in which I plan to make substitution of
`lambda params -> apply method params` requires that I first to fix a
problem in symbol substition.

This situation can arise when the body of this definition:

    def owner1(a: A) = {
        class C extends M[a.B]
    }

is transplanted into a new owner that has a different symbol for `a`.

I speculated that value classes might also be prone to the
fact that symbol substitution neglected `ClassInfoType#parents`.

We can test change with Value Classes:  Partial Functions that are
dependent on value class param type used to fail with a spurious
overriding error, now they work correctly.
Substitute new parameter symbols into lambda body

Previously, new synthetic parameter symbols were created for the
apply method parameters, but only used in its `MethodType`. The
`ValDef` trees of the function, along with their symbols, were
used directly as the parameter trees of the apply method.

    % cat sandbox/test.scala
    object Test {
      (x: Int) => {
        (y: Int) => ???
      }
    }

    % scalac-hash v2.10.3 -Xprint:typer,uncurry -uniqid ../scala2/sandbox/test.scala  | egrep 'syntax|\bx'
    [info] v2.10.3 => /Users/jason/usr/scala-v2.10.3-0-g88b5d19
    [[syntax trees at end of                     typer]] // test.scala
        ((x#12152: Int#351) => x#12152)#12151
    [[syntax trees at end of                   uncurry]] // test.scala
            final def apply#15952(x#12152: Int#351): Int#351 = x#12152

This approach dates back a long way: c64152bc3. @odersky tells me it
was most likely due to insufficent substitution/cloning machinery
at the time.

    % qbin/scalac -Xprint:typer,uncurry -uniqid ../scala2/sandbox/test.scala  | egrep 'syntax|\bx'
    [[syntax trees at end of                     typer]] // test.scala
        ((x#13685: Int#1760) => x#13685)#13671
    [[syntax trees at end of                   uncurry]] // test.scala
            final def apply#13959(x#13960: Int#1760): Int#1760 = x#13960

To make this work, I had to fix a problem in symbol substition; this
was commited in the previous commit. In the enclosed test, at Uncurry,
the symbol of the nested class `N` had a `ClassInfoType`, which listed
as a parent `M[a.C]`. When we substituted the new method parameter
symbol `a` for the eponymous function parameter symbol, this was not
touched.
Refactor away duplication between -Ydelambdafy:{inline,method}
Special treatment for local symbols in TypeTreeMemberType

Avoids calling `thisType` on the owner if it is a term symbol,
which doesn't make much sense.

This method is used internally in tree factory methods that
create, e.g, a `DefDef` based on the info of a `Symbol`.
SI-8001 spurious "pure expression does nothing" warning

`isPureExprForWarningPurposes` doesn’t warn on `()`, but `(): Unit`
leaves it confused. This patch fixes the problem.

The fix is important in the context of the recent split between blackbox
and whitebox macros. Macro engines wrap expansions of blackbox macros
in type ascriptions, so a macro that expands into `()` would actually
produce `(): Unit`, which would trigger a spurious warning. Thanks
@milessabin for spotting this problem!
Merge pull request #3187 from som-snytt/issue/test-suite-quick

Test in quick mode for ant build
Merge pull request #3165 from retronym/ticket/uncurry-tidy-2

Unifying -Ydelambdafy:{inline, method}
Merge pull request #3130 from retronym/ticket/7967-2

SI-7967 Account for type aliases in self-type checks
Merge pull request #3183 from xeno-by/topic/pure-expression-does-nothing

SI-8001 spurious "pure expression does nothing" warning
Merge pull request #3178 from retronym/ticket/7872

SI-7872 Plug a variance exploit in refinement types
Merge pull request #3147 from som-snytt/issue/repl-columns

SI-7969 REPL -C columnar output