Bundle pdftk with the gem

[SirRawlins]

Hi All,

I'd like to propose that we bundle pdftk source code in with the gem to drop the requirement that it be pre-installed on the system. I think this would be beneficial for several reasons:

1. Less work to get up and running, no need to install the dependancy separately in your environment.
2. Versioning of the dependancy is controlled and defined within your app by the gem version, so no risk of the package being updated outside of your codebase and breaking things.
3. Deployment to infrastructure which doesn't allow access to the underlying OS (such as Heroku) would be simplified.

There is already a fairly nice implementation for this kind of thing in the [pdftk-heroku](https://github.com/charliemaffitt/pdftk-heroku) gem. But I think there is a really solid use case for pulling this kind of functionality into active_pdftk natively.

If people are happy with this as a concept I'm happy to put the work in to a pull-request for it.

Thanks,

Robert

[elmatou]

Hi Robert,
Sadly pdftk needs compilation to run on every OS, that mean each distrib has its flavor : x86, arm, win32, osx...
What you can do, is build a activ_pdtk-x86 gem and set the path while constructing the wrapper with the :path options.