* optimize ram block handling
Save the last element of the ram_list. This allows to
faster find where to add new elements when they are not
bigger then page size.
* save ram_list freed
this keeps the optimization for find_ram_offset() intact after snapshot
restore.
* cow only clear the tlb of affected pages
* update flatview when possible
Building each flatview new when the memory has changed is quite
expensive when many MemoryRegions are used. This is an issue when using
snapshots.
* update benchmark for new api
* save flatview in context
this avoids rebuilding the flatview when restore a context.
* init context flatview with zero
* address_space_dispatch_clear remove subpage with higher priority
* docutemnt the options for UC_CTL_CONTEXT_MODE
Specialy stress that with UC_CTL_CONTEXT_MEMORY it is not possible to
use the context with a different unicorn object.
Uses Copy on Write to make it posible to restore the memory state after a snapshot
was made. To restore all MemoryRegions created after the snapshot are removed.
