libstd: Add inttypes for uintptr_t

Signed-off-by: Pawel Dziepak <pdziepak@quarnos.org>
kernel: Add round_down()

Signed-off-by: Pawel Dziepak <pdziepak@quarnos.org>
kernel: Add not_implemented() macro

Signed-off-by: Pawel Dziepak <pdziepak@quarnos.org>
libstd: Rework vsnprintf()

Signed-off-by: Pawel Dziepak <pdziepak@quarnos.org>
libstd: Fix strncmp()

Signed-off-by: Pawel Dziepak <pdziepak@quarnos.org>
kernel: Add functions for mapping continuous memory areas

Signed-off-by: Pawel Dziepak <pdziepak@quarnos.org>