Bumping version to 0.4.3

Bumping version to 0.4.2

Bumping version to 0.4.1

add nib demo、 change the way getting layout cache in `layoutSubviews`

Bumping version to 0.3.1

Merge pull request #16 from molon/dev

Bumping version to 0.3.0

Merge pull request #13 from molon/dev

Bumping the version to 0.2.4

Merge pull request #11 from molon/dev

Bumping the version to 0.2.3

Merge pull request #10 from molon/dev

improve common measure and assert for sublayouts

Merge pull request #9 from molon/dev

fix bug: repeate layout when insert or delete rows