Release targets

[TheGreatSageEqualToHeaven]

• [x] Fix upvalue and similar memory leaks
• [x] Introduce luau_newsettings
• [x] Add namecallHandlers (#19) and macros to settings
• [x] Callback support (#21)
• [x] Support Vector constants
• [x] Update test suite's staging tests and add new tests
• [x] include lineinfo and debuginfo in proto
  • [x] display line in errors.
  • [x] Introduce luau_close