* add memusg to pal_loader script
* Stop bleeding PAL handles.
Deprecating DkOjectReference and reference counting in PAL handle.
Deprecating DkSemaphoreDestroy and DkEventDestroy (replaced by DkObjectClose).
Cleaning unused PAL handles in the library OS.
Adding a heap tracing feature to profile usage of PAL handles.
* fix a bug in SGX mode that mapping untrusted files into memory never got free by DkVirtualMemoryFree()
* adding lighttpd SSL option
* fixing the freeing convention of PAL handles; On SGX, event and mutex handles need to be freed seperately.
* changing how mutexes and events are allocated on SGX
* fixing GCC regression tests (for both Linux and SGX)
* fix a double-free problem of the first thread handle
Chia-Che Tsai