Update of STATUS.devel file for 1.8 release

- removed resolved futures (3)
- added all but 2 as of yet unclassified futures (19)
- updated portability section



git-svn-id: http://svn.code.sf.net/p/chapel/code/trunk@21763 3a8e244f-b0f2-452b-bcba-4c88e055c3ca