Fixed percentile dice

Signed-off-by: Dave <davidajberner@gmail.com>
added 'd' before d100, removed 0 if zero modifier

Signed-off-by: Dave <davidajberner@gmail.com>
Cleaned up code - added comments

Signed-off-by: Dave <davidajberner@gmail.com>
Merge pull request #2 from davislurve/master

Fixed percentage dice