Remove long comment that explains phase ordering issues.

As pointed out by @harrah in #705, we might want to merge both API
and dependency phases so we should mention that in the comment explaining
phase ordering constraints instead.

I'd still like to keep the old comment in the history (as separate commit)
because it took me a while to figure out cryptic issues related to
continuations plugin so it's valuable to keep the explanation around in
case somebody else in the future tries to mess around with dependencies
defined by sbt.

compile/interface/src/main/scala/xsbt/CompilerInterface.scala

@@ -184,43 +184,9 @@ private final class CachedCompiler0(args: Array[String], output: Output, initial
 			val phaseName = Dependency.name
 			val runsAfter = List(API.name)
 			override val runsBefore = List("refchecks")
-			/* We set runsRightAfter to work-around a bug with phase ordering related to
-			 * continuations plugin. See SI-7217.
-			 *
-			 * If runsRightAfter == None, we get the following set of phases (with continuations
-			 * begin enabled):
-			 *
-			 *           typer   4  the meat and potatoes: type the trees
-			 *  superaccessors   5  add super accessors in traits and nested classes
-			 *         pickler   6  serialize symbol tables
-			 *        xsbt-api   7
-			 *    selectiveanf   8
-			 * xsbt-dependency   9
-			 *       refchecks  10  reference/override checking, translate nested objects
-			 *    selectivecps  11
-			 *        liftcode  12  reify trees
-			 *         uncurry  13  uncurry, translate function values to anonymous classes
-			 *
-			 * Notice that `selectiveanf` (one of continuations phases) runs before `refchecks`
-			 * and that causes NPEs in `selectiveansf`.
-			 * However, the default ordering for Scala 2.9.2 is:
-			 *
-			 *          typer   4  the meat and potatoes: type the trees
-			 * superaccessors   5  add super accessors in traits and nested classes
-			 *        pickler   6  serialize symbol tables
-			 *      refchecks   7  reference/override checking, translate nested objects
-			 *   selectiveanf   8
-			 *       liftcode   9  reify trees
-			 *   selectivecps  10
-			 *        uncurry  11  uncurry, translate function values to anonymous classes
-			 *
-			 * Here `selectiveanf` runs after refchecks and that's the correct ordering. The
-			 * true issue is that `selectiveanf` has hidden dependency on `refchecks` and
-			 * that bites us when we insert xsbt-dependency phase.
-			 *
-			 * By declaring `runsRightAfter` we make the phase ordering algorithm to schedule
-			 * `selectiveanf` to run after `refchecks` again.
-			 */
+			// keep API and dependency close to each other
+			// we might want to merge them in the future and even if don't
+			// do that then it makes sense to run those phases next to each other
 			val runsRightAfter = Some(API.name)
 		}
 		with SubComponent
@@ -276,7 +242,7 @@ private final class CachedCompiler0(args: Array[String], output: Output, initial
 			for( (what, warnings) <- seq; (pos, msg) <- warnings) yield
 				callback.problem(what, drep.convert(pos), msg, Severity.Warn, false)
 		}
-		
+
 		def set(callback: AnalysisCallback, dreporter: DelegatingReporter)
 		{
 			this.callback0 = callback