added description parameter for Fuel_module
updated Fuel_layouts::get method so it can return an array of either all page or block layout objects
added submodule and install_info methods to Fuel_advanced_module library
Added a better default set of client specific documentation.
fixed issue with previous changes to Fuel_layout::get layout
added description area for simple modules
helper file link updates to the documentation
fixed typo for webhook_remote_ip config parameter
added placeholder image function to asset_helper