Fix Bind node contents not being transformed if phase didn't register transformBind.
Merge pull request #291 from dotty-staging/fix-transform-bind

Fix Bind node contents not being transformed if phase didn't register transformBind.
Make Bind nodes type trees depending on bound name.

Bind nodes were always TermTrees, which is wrong.
Fix typechecking rules for Binds of type trees.
Avoid spurious warnings about forward references in refinements

The warning was triggered by cases like:
class A
type F = A { type T = Int; def f: T }
Which is treated differently from the following which did not produce a warning:
type F = A { type T = Int } { def f: T }
Merge pull request #293 from smarter/fix/multiple-refinements-warning

Avoid spurious warnings about forward references in refinements
Merge pull request #292 from dotty-staging/fix/#290-type-bind

Fix/#290 type bind
Sharing backend between scalac and dotty.

Due to a lot of error and workarounds required for backend not regress in terms of speed, I guess the original idea was to high to be reached..
Nevertheless it was good to try.
Erasure is on by default.

Remove historical enabling of erasure for some tests: its enabled by default now
Update to scala 2.11.4
Hack ClassFileParser to not treat Null$ or Nothing$ as modules.

They are classes.
Move methods shared between Mixin and Backend to SymUtils.
Remove duplicate isAnonymousFunction
New phase: collectEntryPoints

collects entry points and registers them in backend
Depend on custom compiler with https://github.com/scala/scala/pull/4136 incorporated
remove dependency on Btypes from DottyPrimitives. Rely on symbols instead.
GenBcode phase implemented.

That doesn't mean it works :-)
Add member lookups needed by backend.
Complete DottyBackendInterface.
Enable new phases.