More descriptive PPLNS options
More descriptive PPLNS options

Fixes #421 and #422

studio666/php-mpos,nimblecoin/web,ychaim/php-mpos,shreeneve/test,mculp/chunky-mpos,mmitech/php-mpos,evgenyponomarev/pool,ychaim/php-mpos,sasselin/xcoin-mpos,nimblecoin/web,machinecoin-project/php-mpos,sasselin/xcoin-mpos,UNOMP/chunky-mpos,shreeneve/test,evgenyponomarev/pool,CoinHashMe/MPOS-SSO,mculp/chunky-mpos,CoinHashMe/MPOS-SSO,mculp/chunky-mpos,xisi/php-mpos,shreeneve/test,bankonme/php-mpos,machinecoin-project/php-mpos,xisi/php-mpos,UNOMP/chunky-mpos,evgenyponomarev/pool,mculp/chunky-mpos,sixxkilur/php-mpos,MPOS/php-mpos,nimblecoin/web,machinecoin-project/php-mpos,CoinHashMe/MPOS-SSO,MPOS/php-mpos,CoinHashMe/MPOS-SSO,xisi/php-mpos,bankonme/php-mpos,mmitech/php-mpos,studio666/php-mpos,BlueDragon747/php-mpos,CoinHashMe/MPOS-SSO,MPOS/php-mpos,UNOMP/chunky-mpos,BlueDragon747/php-mpos,sixxkilur/php-mpos,bankonme/php-mpos,UNOMP/chunky-mpos,ychaim/php-mpos,sixxkilur/php-mpos,BlueDragon747/php-mpos,studio666/php-mpos,mmitech/php-mpos,sasselin/xcoin-mpos