Multiple bugfixes

[mirabilos]

• Fix buffer overflow (origin/bugfixes, bugfixes) (buffer overflow, should say enough)
• Fix Undefined Behaviour due to pointer aliasing (pretty relevant, compiler can produce broken code from this bug)
• Use same type to store the result as the API returns (API returns int so store it as such, not as unsigned long)
• Insert missing reference operator (just a missing & the compiler noticed)
• Fix bad nroff syntax in manpage (this led to an nroff warning and bad output)