removed builtin pow, and replaced it with bitwise xor

Signed-off-by: Alexander Skjolden <alex@plastboks.net>
pow function for standard library

Signed-off-by: Alexander Skjolden <alex@plastboks.net>
increment and decrement builtin operators

Signed-off-by: Alexander Skjolden <alex@plastboks.net>
make use of the new "--" and "++" operators in standard library

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