PDF and Office format versions and passwords

[vatterspun]

So this isn't a proper bug report because I've basically had a few problems over the past year that I didn't take down specifics on. If this is interesting, I can do a bit more digging into this and see what works and what does not. Just wanted to see if anybody cared.

• Some PDF formats can't be encrypted/decrypted by ExcelPass. I think PDF 1.7 for example supports a different encryption AES vs. ExcelPass' RC4. ExcelPass works on the latter.
• Earlier versions of Microsoft Office use very basic, easily-cracked encryption while later versions (I think 2007 and above) use standard crypto that can't be read by many "office-compatible" programs.