Memory allocations logger

To track the use of memory in SWIFT this change adds an optional logger that logs all the calls to the swift_memalign, swift_malloc, swift_calloc and swift_free functions. These logs can be dumped to form a labelled timeline of allocation and deallocation, which can be post processed to also report the amount of memory in use.

When enabled and the application exits using the error() macro an attempt to dump the current allocations is made, this will include the failed memory allocation if that was the call that generated the error.

Fixes #414 (closed) and supersedes !527 (closed)