great renaming propagation: syntax
Remove extra
auto merge of #7365 : cmr/rust/syntax_cleanup, r=Aatch

Sets the stage for further cleanup (especially mass-slaughter of `@`)
Change finalize -> drop.
auto merge of #7269 : luqmana/rust/drop, r=thestinger

Finally rename finalize to drop.
Closes #4332.
More 0.7 release notes