Added extend loadDefaults options
Added extend loadDefaults options

Options extension to provide a loadDefaults object. This will give the option to disable 4 different options angular, angular-animate, marked, and prettify (google) which usually get loaded through defaultScripts.

This would give the user the ability to disable any scripts if they are using methods outside of regular angular/animate loading like browserify .
cpaof/gulp-ngdocs,Thellior/gulp-ngdocs,heran/gulp-fakedocs,manuelro/gulp-ngdocs,hans-helms/gulp-ngdocs,paul-barry-kenzan/gulp-ngdocs,michaelbazos/gulp-ngdocs,whitneyit/gulp-ngdocs-manuelro,alizarion/gulp-ngdocs,nikhilmodak/gulp-ngdocs