Modified Exception type.

Others:
Fixed variable names to stop reassignment.
Updated: copyright comments.
Merge branch 'fix' of https://github.com/trashtoy/PEACH into fix
Merge branch 'fix' of https://github.com/trashtoy/PEACH into fix
Merge branch 'fix' of https://github.com/trashtoy/PEACH into fix
fixed #1

Detail:
- Modified containsKey from isset() to array_key_exists()
Merge branch 'fix' into develop