SI-5784 Scaladoc: {Abstract,Alias} type templates

Normally scaladoc won't generate template pages for anything other than
packages, classes, traits and objects. But using the @template
annotation on {abstract,alias} types, they get their own page and take
part as full members in the diagrams. Furthermore, when looking for the
companion object, if a value of type T is in scope, T will be taken as
the companion object (even though it might be a class)

All templates, including types are listed on the left navigation pane,
so now adding @template to String can get scaladoc to generate (a
no-comments) page for java.lang.String.

The {abstract, alias} type icons need to be updated -- I just took the
class icons and added a small x to them -- but they shoud be something
else (maybe an underscore?)i

TO USE THIS PATCH:
<pre>
/** @contentDiagram */ // tells scaladoc to create a diagram of the
                       // templates contained in trait Base
trait Base {
  /** @template */ // tells scaladoc to create a page for Foo
  type T < Foo
  trait Foo { def foo: Int }
}

/** @contentDiagram */
trait Api extends Base {
  /** @template */
  override type T <: FooApi
  trait FooApi extends Foo { def bar: String }
}
</pre>

1 files changed, 5 insertions, 5 deletions

diff --git a/src/compiler/scala/tools/nsc/doc/model/Entity.scala b/src/compiler/scala/tools/nsc/doc/model/Entity.scala
index 620aa4253f..0836d7e4da 100644
--- a/src/compiler/scala/tools/nsc/doc/model/Entity.scala
+++ b/src/compiler/scala/tools/nsc/doc/model/Entity.scala
@@ -241,6 +241,11 @@ trait MemberTemplateEntity extends TemplateEntity with MemberEntity with HigherK
   /** The value parameters of this case class, or an empty list if this class is not a case class. As case class value
     * parameters cannot be curried, the outer list has exactly one element. */
   def valueParams: List[List[ValueParam]]
+
+  /** The direct super-type of this template
+      e.g: {{{class A extends B[C[Int]] with D[E]}}} will have two direct parents: class B and D
+      NOTE: we are dropping the refinement here! */
+  def parentTypes: List[(TemplateEntity, TypeEntity)]
 }
 
 /** A template (class, trait, object or package) for which documentation is available. Only templates for which
@@ -259,11 +264,6 @@ trait DocTemplateEntity extends MemberTemplateEntity {
     * only if the `docsourceurl` setting has been set. */
   def sourceUrl: Option[java.net.URL]
 
-  /** The direct super-type of this template
-      e.g: {{{class A extends B[C[Int]] with D[E]}}} will have two direct parents: class B and D
-      NOTE: we are dropping the refinement here! */
-  def parentTypes: List[(TemplateEntity, TypeEntity)]
-
   /** All class, trait and object templates which are part of this template's linearization, in lineratization order.
     * This template's linearization contains all of its direct and indirect super-classes and super-traits. */
   def linearizationTemplates: List[TemplateEntity]