WIP: Documentation enhancement; related to #1750

This MR reorganizes how man pages are installed, installs general guide PDFs on all platforms, only installs man pages on non-Windows systems, and installs PDF versions of the man pages only on Windows systems. More detail is provided in #1750 (closed). This has been tested with ZIP archives on both Linux Mint (Ubuntu-ish) and Windows 8.1. It should only touch man pages and PDFs and not affect code.