Thanks for the link. I was also wondering, when you import the assets from the store, do you need to import all? Is the demo folder required?
For my gitignore, I ended up with:
obj/
Temp/
*.svd
*.suo
*.user
*.pidb
*.userprefs
*.unityproj
.DS_Store
Library/*
!Library/*.asset
Temp
*.pidb
build
Assets/TK2DROOT/tk2d_demo/*