characters should not be able to roll off platforms/stages

[pzhang87]

Fantasy Crescendo Version: v0.4.0 development-64-bit Build #435
Operating System: WIndows 10
Expected Behavior: If a character enters a roll and is standing near the edge of a platform/stage, character's horizontal position should be stopped at the edge of the stage.
Actual Behavior: If a character enters a roll and is standing near the edge of a platform/stage, character will travel the full horizontal distance of the roll (along with any associated vertical fall distance). The character will then also enter a shielding state temporarily upon completion of the roll, regardless of whether the character is grounded or airborne.