ported key formats code over to libwallet.
moved select_outputs to libwallet.
cleaned up and fixed txpool validate code.
tidied up serialize code.
remove determ from examples.
updated quickstart doc.
crypto stuff now uses libwallet.
comments for sighash script stuff
remove redundant chain reference in leveldb_organizer (only base organizer needs it)
update last checkpoint to block 278700
set checkpoint to 702
bump version number to 2.0