update 2 command-line parameter help messages
update 2 command-line parameter help messages

- -checkpoints is now much more understandable and should be way easier
  to translate
- -loadblock uses the same format (blk000??.dat) as -reindex

domob1812/crowncoin,Crowndev/crowncoin,syscoin/syscoin,Infernoman/crowncoin,Crowndev/crowncoin,Infernoman/crowncoin,domob1812/crowncoin,syscoin/syscoin,syscoin/syscoin,dobbscoin/dobbscoin-source,syscoin/syscoin,Earlz/dobbscoin-source,syscoin/syscoin,dobbscoin/dobbscoin-source,Infernoman/crowncoin,Earlz/dobbscoin-source,Earlz/dobbscoin-source,Crowndev/crowncoin,Crowndev/crowncoin,syscoin/syscoin,Infernoman/crowncoin,Infernoman/crowncoin,Crowndev/crowncoin,Earlz/dobbscoin-source,domob1812/crowncoin,dobbscoin/dobbscoin-source,dobbscoin/dobbscoin-source,domob1812/crowncoin,dobbscoin/dobbscoin-source,Infernoman/crowncoin,domob1812/crowncoin,syscoin/syscoin,syscoin/syscoin,Earlz/dobbscoin-source,dobbscoin/dobbscoin-source,domob1812/crowncoin,Earlz/dobbscoin-source,Crowndev/crowncoin