Implemented vm::var.
MemoryAllocator replaced with vm::var
Fixed compilation errors
Implemented vm::ptr & vm::ref
(nothing, really)
Some warnings fixed, some code removed
Some warnings fixed
Some warnings fixed
memory-wip branch merged
Compilation fix
Compilation fix 2
Compilation fix 3
Test
Compilation fix
vm::ptr for u8/char types, mem_list_ptr_t removed
Compilation fix
Compilation fix 2
Compilation fix 3
Bug fixed
Bugs fixed
mem16_t replaced

I think it's not bad to use pointer type when possible, because it's
often originally pointer, not reference.
mem64_t replaced

Added conversion from vm::var to vm::ptr of the same type.