key is unaltered
remove unused AA vararg functions
remove old TODO comment

- We are not going to replace the current AA signatures which take
  an extra parameter for the value size, because getting it from
  TypeInfo_AssociativeArray instead required another virtual call.
remove dead&rotten code
opaque AA Range interface
Merge pull request #549 from dawgfoto/cleanupAA

Cleanup AA
Merge pull request #511 from dawgfoto/internalizeAA

opaque AA Range interface
dmd no longer uses this list on linux
Merge pull request #552 from dawgfoto/removeModuleRef

dmd no longer uses this list on linux