Warn about locally identifiable init order issues.

This warns about a subset of initialization order issues which
can easily be identified by inspection, such as

  val x = y
  val y = 5

The likelihood of this formulation being intentional is miniscule.
update eclipse projects (partest, repl & scaladoc)

Since we've removed scala.annotations.serializable in 2.11,
you'll need to following bandaid to use eclipse on master.

This is the easiest fix, but certainly not recommended in general.

```
--- i/src/eclipse/scala-library/.classpath
+++ w/src/eclipse/scala-library/.classpath
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <classpath>
        <classpathentry kind="src" path="library"/>
-       <classpathentry kind="con" path="org.scala-ide.sdt.launching.SCALA_CONTAINER"/>
+       <classpathentry exported="true" kind="con" path="org.scala-ide.sdt.launching.SCALA_CONTAINER"/>
```

This corresponds to checking the export check box for the scala library jar
in the library's build path.
Merge pull request #2241 from adriaanm/eclipse-repl

update eclipse projects (partest, repl & scaladoc)
Merge pull request #2240 from paulp/pr/warn-forward-reference

Warn about locally identifiable init order issues.