kmalloc() and free()

Now, the heap memory management system seems pretty solid; malloc()
and free() work in the kernel land with heaping and paging. Yay!

Expanding and contracting of the heap is still a WIP though..
heap expands on demand
Bug fix

Fix bug where heap expansion caused problems with recalculating space
taken by memory chunks upon allocation or free-ing.
Merge branch 'master' of https://github.com/razbit/razos
Heap memory management now works