jvalenzuela

An initial pass on an API is in the buf branch of my fork: https://github.com/jvalenzuela/OpENer/tree/buf. Doxygen documentation is included, so it can be reviewed via make doc.

This has been corrected in the set of commits I'm submitting for addressing compiler warnings, and is also a rather good example why warnings should not be ignored and allowed...

I realize this is a lot of changes. I can help make it easier to merge, perhaps selecting one commit at a time to consider, then reorder or rebase it...

Ok, I'll close this pull request, rebase as needed, and open new pull requests for each.

Here's one of the files causing the problem. Starting with some other page from another document, then calling mergePage() with this PDF results in the above error. [108.pdf](https://github.com/mstamy2/PyPDF2/files/331139/108.pdf)