SI-5235 Correct usecase variable expansion

The bug is related to a couple of other annoyances, also fixed:
 - usecases without type params were crashing scaladoc due to a change
in the PolyTypes class (not allowing empty tparams list)
 - properly getting rid of backticks (even if the link is not valid)
 - correct linking for usecases with $Coll = `immutable.Seq`
(the symbol searching algorithm was too of restrictive, now we search
the entire ownerchain - and the empty package at the end)
 - give a warning if the type lookup fails
 - finally, added a $Coll variable to List, for some reason it wasn't
there and we were getting immutable.Seq as the result of use cases.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/library/scala/collection/immutable/List.scala b/src/library/scala/collection/immutable/List.scala
index 6fd8d143ee..74dc385f99 100644
--- a/src/library/scala/collection/immutable/List.scala
+++ b/src/library/scala/collection/immutable/List.scala
@@ -62,6 +62,7 @@ import java.io._
  *  section on `Lists` for more information.
  *
  *  @define coll list
+ *  @define Coll `List`
  *  @define thatinfo the class of the returned collection. In the standard library configuration,
  *    `That` is always `List[B]` because an implicit of type `CanBuildFrom[List, B, That]`
  *    is defined in object `List`.
@@ -96,7 +97,7 @@ sealed abstract class List[+A] extends AbstractSeq[A]
    *
    *  @usecase def ::(x: A): List[A]
    *    @inheritdoc
-   *    
+   *
    *    Example:
    *    {{{1 :: List(2, 3) = List(2, 3).::(1) = List(1, 2, 3)}}}
    */