Readded Seedhash to FRKHASH to pascify FRKMINER

Istanbul: Update Hardfork Blocknumber to 3,050,000

Constantinople: Pirl Guard

Merge pull request #27 from expanse-org/v1.7.x

V1.7.2

Merge pull request #27 from expanse-org/v1.7.x

V1.7.2

Merge pull request #19 from expanse-org/v1.6.x

V1.6.6

update version to 1.6.1 beta

update version to 1.6.1 beta

merge cleanup

good bye old friends.

Merge pull request #16 from expanse-project/rebase-1.4.16

Rebase 1.4.16