add collision detection
set scoring condtions
spawn multiple falling objects
recommit of issue#9
fix issue #9
update issue#9
Merge pull request #1 from ajoshdee/issue#8

Issue#8
Revert "Merge pull request #1 from ajoshdee/issue#8"

This reverts commit ff8e62555d7c17c1923804525f000234c20abbeb, reversing
changes made to d5623d173f1e0e4e03dbcef3ca383c81eab7bf19.
Revert "Revert "Merge pull request #1 from ajoshdee/issue#8""

This reverts commit 90c958ee900a8488494f71ce6d97d2e2192ce0b8.
fix conflict
Merge branch 'issue#9' into dev_1.0
fix conflict