Add a --require option

[MadBomber]

When using the embedded ruby (--erb) option to indicate that the prompt file needs to be pre-processed through the ERB system, that embedded code may need access to Ruby libraries.

aia prompt_id --erb --require lib1,lib2,lib3 --shell

should pre-load all of the libaries so that the ERB code can access the classes as necessary. FOr example, if you have ActiveRecord classes that you want the ERB code to reference as part of the prompt generation process.

[MadBomber]

within the context of the prompt file, inside the ERB you can also do require statements. This new --require options only purpose seems to be to DRY up multiple prompts.