Added file exists check in autoloader
Added file exists check in autoloader

When using an external library, many come with their own autoloaders. If
the class we want does not exist in our code, return false from this
autoloader so others can get a chance to run, instead of allowing this
one to throw an error and crash the application.

TexasLAN/Omega,TexasLAN/Omega,leftees/nucleus,hacktx/nucleus,analytalica/nucleus,analytalica/nucleus,leftees/nucleus,jlciam/Omega,hacktx/nucleus