Reflection no longer produces faux existentials

Because of using plain ExistentialType factory of a case class
typeToScala sometimes returned existentials with empty quantifieds.

Changing ExistentialType to newExistentialType, which simply returns
the underlying types if params are empty, fixed the problem.
SI-6374 Reflection now works for anns with enum fields

Enum members are static and, therefore, they need to be looked up in
classSymbol(<enum>).companionModule, rather than in classSymbol(<enum>).
Merge pull request #1320 from scalamacros/topic/is-implicit

moves isImplicit from TermSymbol to Symbol
Fixes SI-6337 by disallowing nested value classes.

It seems for the moment too hard to allow this, and the functionality to have value classes wrap other value classes does not seem essential.
Fixed comment.
refactors java reflection tests

All javac-produced artifacts are now placed into test/files/lib
Merge pull request #1321 from namin/apply-dynamic-sugar

Fixed SI-6353: applyDynamic with sugared applications
Revert "Fix SI-6294."

This reverts commit cb393fcbe35d0a871f23189d791b44be1b826ed2.

Conflicts:

	src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
Revert "Fix SI-4581."

This reverts commit 373f22a2022519ab894c1ea77460e6460d7c2ee4.
Revert "Fixes SI-6236."

This reverts commit faa114e2fb6003031efa2cdd56a32a3c44aa71fb.
Revert "Fixes SI-6189."

This reverts commit 5a8dfad583b825158cf0abdae5d73a4a7f8cd997.

Conflicts:

	src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
Revert "WIP add private/lazy checks and a few tests."

This reverts commit 227239018b38ab7218ee6b30493c9c8e1836c8c9.
Revert "Implement @static annotation on singleton object fields."

This reverts commit 892ee3df93a10ffe24fb11b37ad7c3a9cb93d5de with
exception of keeping `@static` annotation in the library so we
can deploy a new starr that does not depend on it before removing
it completely.

Conflicts:

	src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
	src/compiler/scala/tools/nsc/backend/jvm/GenJVM.scala
	src/compiler/scala/tools/nsc/transform/CleanUp.scala
Merge pull request #1291 from vjovanov/actor-migration-tests

Fix for SI-6305 & new actor migration tests 
SI-6287 fixes synthetic symbol clashes in toolbox

Apparently synthetic classes like $anonfun$1 have two properties:
1) Their names are generated using a counter unique to a compilation unit
2) After flatten they levitate to the nearest enclosing package

As a result if we use an empty package to wrap toolbox codegen,
then this package will soon be overflown by $anonfun$1 symbols, because:
1) New codegen session = new compilation unit = new counter which starts at 0
2) New codegen session = new anon funs that end up as children of empty package

Creating a freshly named package for each codegen session fixed the problem.
Now anonfuns from different sessions end up with different parents.
SI-5942 toolboxes now reset front ends

FrontEnd => Reporter proxy now correctly redirects
flush and reset back to the underlying front end.
SI-5692 better error message

Doesn't fix the underlying issue with macros and type inference,
but at least now the error message says exactly what needs to be done
to make the error go away.
pull request feedback
Merge pull request #1249 from vigdorchik/cleanup_shadowing_table

Cleanup makeShadowingTable, save some memory. Review by @VladUreche or @...
Merge pull request #1328 from scalamacros/ticket/5942

SI-5942 toolboxes now reset front ends