ENH: cleanup and rationalize memory-backed streams

- more consistent naming:
  * Versions that hold and manage their own memory:
      IListStream, OListStream

  * Versions that reference a fixed size external memory:
      UIListStream, UOListStream

- use List storage instead of DynamicList within OListStream.
  Avoids duplicate bookkeeping, more direct handling of resizing.

applications/test/IListStream/Make/files

@@ -0,0 +1,3 @@
+Test-IListStream.C
+
+EXE = $(FOAM_USER_APPBIN)/Test-IListStream