Harden asInstanceOfOpt to be robust for nulls or reflection crashes.
Don't create a reconciler for non-editor source configurations.

In the Syntax Coloring preview pane we create a source viewer without an
editor. The reconciler needs an editor to get to the compilation unit, so
we don't attach a reconciler in this case (there won't be any editing).

We might need to revisit this if we ever want to use a source viewer outside
an editor (with reconciliation capabilities).
Merge pull request #596 from dragos/issue/fix-quiescence-syntax-coloring-window-crash

Fix syntax coloring window crash
Unused member warning doesn't highlight whole definition anymore

This change can only be seen when the `-Xlint` setting is set. The
warning about unused members is introduced for SI-440.

Previously, the whole definition is highlighted by an unused member
warning, which was very annoying. The new behavior only highlights their
names.

The fix will also affect any other error message that highlights a whole
expression or definition.

No tests included because I have no idea on how to test the behavior.
Only some manual tests were done:

    class MyClass {
      private def hello(i: Int) = { // <--
        println(i)
        i
      }

      private val abc = { // <--
        0
      }

      def ghi = {
        val abc = { // <--
          0
        }
        5
      }

      private class Xros { // <--
        val xxx = 0
      }
    }

Fixes #1001983
Merge pull request #591 from sschaef/t1001983-fix-pos-of-unused-member-warning

Unused member warning doesn't highlight whole definition anymore
Lets the sdt.core pom.xml copy scala-reflect from the m2repo to the target folder

Fixes #1001987
Merge pull request #601 from huitseeker/issue/1001987

Lets the sdt.core pom.xml copy scala-reflect from the m2repo to the target folder