internal: add macro to round value to the next closest power of 2

There are two special cases, if the input number is 0 or the number is
larger then 2^31 (for 32bit unsigned int). For the special cases the
return value is 0 because they cannot be rounded.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>

bootstrap.conf

@@ -35,6 +35,7 @@ clock-time
 close
 connect
 configmake
+count-leading-zeros
 count-one-bits
 crypto/md5
 crypto/sha256