(no changes, just re-ordered)

We added QPDF-367-0.pdf as a regression test, but it also contains
a different type of signature we don't currently support.

Since we already have it in tree extend the regex to also detect it.

The regex used to detect signatures uses "(.|\\s)" to emulate dotall, since
old browsers don't support it.

For some reason that leads to internal errors in Firefox with larger files in some cases.

Replacing it with a simpler "[\\s\\S]" class makes things work.

Also adds some tests with real PDF files, "QPDF-367-0.pdf" was triggering this issue.

Fixes #46

The backend now requires a profile ID to be passed. It still
is optional for now, but this allows us to make it required in the future.

Handle the new and old naming for now

This reverts commit 5ffa18ef.