add options for each engine. extracted from global setting Onebox.options based on class name
add options for each engine. extracted from global setting Onebox.options based on class name

To set options for the engine github_blob_onebox.rb 
Onebox.options = {
  GithubBlobOnebox => {:SHOW_LINE_NUMBER => true}
}

then from within the engine instance engine options can be accessed 
self.options[:SHOW_LINE_NUMBER]
or get all options using
Onebox.options
aceofspades/onebox,tarzan/onebox,discourse/onebox,billy3321/onebox,techAPJ/onebox,techAPJ/onebox,billy3321/onebox,discourse/onebox,billy3321/onebox,tarzan/onebox,aceofspades/onebox,aceofspades/onebox,techAPJ/onebox,tarzan/onebox