[axl_enc] removed default (=NULL) for actual takenSize in CodePointDecoder
[axl_enc] removed default (=NULL) for actual takenSize in CodePointDecoder

it encourages misuse (like the latest bug in ninja-scroll where takenSize was calculated as a sum of cpl's)

vovkos/axl,vovkos/axl,vovkos/axl,vovkos/axl