Always use debugging options in CMake build
Fix compile error looking for MAXPATHLEN
Disable copy-on-write by making all array functions always copy

Currently has issues
Remove more instances of hasMultipleRefs
Remove usages of hasExactlyOneRef

Currently untested
Fix failing array_plus_eq test
Fix curl_copy_handle tests.

I'm not really sure how they were passing in the first place, and
what I did to make them fail.
Allow arrays to not be copied when adding a new key.

Fixes failing serialisation tests
Fix invalid array copy sometimes breaking array_multisort
Start working on a version which only refcounts ref-data objects
Remove a lot of assertions which no longer apply.

JIT does not work. Wordpress appears to mostly work in interpreter
mode
Disable tests which depend on precise destruction

Might want to rewrite these (or, indeed, part of the test script)
so that they work again in the future.
Rewrite the test suite so that object IDs in var_dumps are ignored

Removing precise destruction means that object IDs can no longer
be identical to what is expected by zend. This is not a bug, so
I'm rewriting the test cases so they can continue to be useful.

The python script used can be seen at
https://gist.github.com/tgsergeant/5189e02bc934db9e2210
Try and make the JIT ignore all reference counts except for RefData
Remove errant release calls

If we block-allocate an object, we have to make sure it's not being
released through the conventional means. If it is, it's going to
end up on a freelist, and then could be double-allocated later on.
Initial work on a tracing garbage collector
Further attempts to trace the heap
Appear to be successfully tracing the heap
Cleaned up tracing
Change MarkSweepCollector to a thread-local singleton