Lots of fixes, less memory used, more decoupled interface, tons of bug fixes
Fixed memory leak issue, added memtest.js
Added memory test
More memory fixes/tests
Added two unit tests, fixed ut issues

Modified memtest.js, added struct-test.js, fixed many unit test issues.
Added authors/contributors doc
Fixed nserror.js unit tests
Fixed extend.js
Fixed error in NSLog.js unit test
Fixed id-methods.s unit test issue.
Fixed failing swizzle-dealloc.js unit test.
Fixed array-references.js required A LOT of changes

To fix array-reference.js unit test it required completely decoupling
id/class so that obj_getAssociatedObject/obj_setAssociatedObject would
not leak memory.  This is now fixed, sorry for the large commit.  Also,
moved “core” unit tests into an archive, the inner (private) api for
core has changed, unsure if its necessary to keep these in sync.
Fixes for pull request on 0.1.0 add global, minor unit tests
package: fix "ffi" dependency name
package: add "ref" and "ref-struct" as dependencies
package: remove "engines" section
test: add `global` mode test file
re-add removed `global.js` file

Inadvertently removed in 72976516fc335ace99a9a2b5ff8f45d2803c7acf.
Fixed global functionality
index: fix trailing whitespace