Delete MAPL2 module and MAPL/ subdirectory (#4890)

* Remove MAPL_SUPPORT_MAPL3 ifdefs; MAPL2 module no longer needed (refs #4888)

* Delete MAPL/ subdir; superseded by mapl3g/ for MAPL umbrella target (refs #4888)

Author: tclune

CMakeLists.txt

@@ -233,7 +233,6 @@ add_subdirectory (state)
 add_subdirectory (shared)
 add_subdirectory (include)
 add_subdirectory (base3g)
-add_subdirectory (MAPL)
 add_subdirectory (mapl3g)
 add_subdirectory (utilities)
 add_subdirectory (gridcomps)