Made associative domains/arrays shrink on remove
Made associative domains/arrays shrink on remove

Improved the associative domain/array implementation
such that calling the remove method will cause the
table size to be approximately halved when it is
sufficiently empty (< 1/8 full).



git-svn-id: 88467cb1fb04b8a755be7e1ee1026be4190196ef@13744 3a8e244f-b0f2-452b-bcba-4c88e055c3ca

hildeth/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,hildeth/chapel,sungeunchoi/chapel,hildeth/chapel,chizarlicious/chapel,chizarlicious/chapel,sungeunchoi/chapel,chizarlicious/chapel,chizarlicious/chapel,sungeunchoi/chapel,chizarlicious/chapel,chizarlicious/chapel,hildeth/chapel,chizarlicious/chapel,sungeunchoi/chapel,sungeunchoi/chapel,CoryMcCartan/chapel,hildeth/chapel,sungeunchoi/chapel,CoryMcCartan/chapel,hildeth/chapel,hildeth/chapel,sungeunchoi/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,sungeunchoi/chapel,CoryMcCartan/chapel