Increase the initial VM mapping to 16MB.
Remove BOOT_STACK_* defines, noone used them..
Use a loop to map BOOT_MAX_MAPPED pages.
Allow to query free bootstrap mem / bounds checking.
Fix set_page_physical_base_offset(), enforce 16MB memory requirement.
Fix read_/write_cr* for 64bit mode.
Force __ebootstrap to 4K alignment.
First rough virtmm version.