Disable payment protocol pending further assessment and potential rework.
Replaced tabs with spaces.
Merge pull request #491 from rnicoll/1.7-dev-no-payment

Disable payment protocol pending further assessment and potential rework
Inserted checkpoints through the 100k-200k block range, with emphasis on the 145k
(hard fork) and 200k (second reward halving) blocks.
Corrected timestamp on most recent checkpoint block; previous epoch value was incorrect
when calculating timestamp.
Merge pull request #492 from rnicoll/1.7-checkpoint

Add 100k-200k checkpoints
Renamed release notes to remove reference to alpha.
Marked build as production read and removed beta tag in preparation for RC release.
Merge pull request #493 from rnicoll/1.7-dev-rc

Prepare development branch for release candidate
refactor GetMinFee to remove dead code
don't send feeless transactions
add travis check for disable-wallet compile mode
speed up Travis CI build
add ccache to Travis config
move GetPoWHash to CBlockHeader class
update and enhance qt project file
Merge pull request #497 from leofidus/travis-nowallet

Add travis check for disable-wallet compile mode
Merge pull request #498 from leofidus/1.7-GetPoWHash

move GetPoWHash to CBlockHeader class
Merge pull request #499 from leofidus/qtproject

update and enhance qt project file
Merge pull request #496 from leofidus/1.7-fees

fee changes