Merge pull request #61 from makotok/dev

The merged into master branch from the development branch
Merge branch 'master' of github.com:makotok/Hanappe
Merge branch 'dev'
#54 Improved cost of object creation

Compatible collapse Portions of this fix.
However, consumption of memory is improved obviously.
#68 TileObject visibility bug in Flower
#69 setGid doesn't work with "unused" tiles.
update sample
Merge branch 'use_interface'