Added logic for adding sections.

1.4.0

Added logic for adding items.

Return to default system.

1.3.8

Return to default system.

Fixed logic after reoder.

1.3.7

Fixed logic after reoder.

Fixed updating snapshot logic.

1.3.6

Fixed updating snapshot logic.

Fixed order bugs.

1.3.5

Update SPDiffable.podspec

Added manage order in sections.

1.3.4

Added manage order in sections.

Fixed bugs for collection flow layout capabilities.

1.3.3

Fixed pass value in collection view init.

Update collection views inits and docs.

1.3.2

Update collection views inits and docs.

Fixed `headerAsFirstCell` flag.

1.3.1

Fixed `headerAsFirstCell` flag.

Fixed `headerAsFirstElement` flag.

1.3.0

Fixed `headerAsFirstElement` flag.