better fibonacci function

Signed-off-by: Alexander Skjolden <alex@plastboks.net>
Merge branch 'master' of https://github.com/plastboks/Byol
removed power function in stdlib

Signed-off-by: Alexander Skjolden <alex@plastboks.net>
reimplmented pow function as builtin

Signed-off-by: Alexander Skjolden <alex@plastboks.net>