* Added instructions for Windows 7, but only for Bitcoin Core GUI. I
added a stub for anyone who wants to write instructions for using the
daemon on Windows.
* Added instructions for Ubuntu 14.04 LTS Server, but only for Bitcoin
core daemon. I assume most server users run headless.
* Added instructions for Other Linux Distributions, for both GUI and
daemon. Hopefully the instructions are general enough to apply to most
distributions but specific enough that they actually help readers.
* Added a stub for Windows 8.1 as I don't have access to a copy, and all
the pay-per-hour Windows VPSes I can find run some version of Windows
Server. (I have the same problem with OS X.)
* Hid some subsections in the table of contents: I found having
subsections named "Bitcoin Core GUI" and "...Daemon" within multiple
sections distracting, so I hid them in the TOC.
* Added basic PGP verification instructions: I didn't try to explain PGP
to newbies, but I did provide instructions useful to people who have
used PGP before. These instructions are currently displayed in the
Windows 7 and Other Linux Distributions sections (where users download
from Bitcoin.org).
* Made sure the end of each install section points to the Network
Configuration section so users open port 8333.
Closes#410