优化缩放效果
Merge branch 'release-1.2.0' of github.com:fex-team/kityminder into release-1.2.0
Merge branch 'release-1.2.0' of github.com:fex-team/kityminder into release-1.2.0
bug fix
Merge branch 'release-1.2.0' of github.com:fex-team/kityminder into release-1.2.0
fix delete node bug