fixes weird bounce
fixes walking into slopes broke standing on points
Fixed link to point to the right website
moved backdrop above bridge downward a little
No more bouncing
Merge pull request #1234 from blha303/spellcheck

Fixed link in CONTRIBUTING.md to point to the right website for sound file uploading
Merge pull request #1230 from CalebJohn/polygon-fix

Removes bounce at edge of polygons
Merge pull request #1237 from ExplosiveOctopus/test_branch

moved backdrop above bridge downward a little