Uses Ruby html-proofer to check the links. This commit also fixes the
various problems it found, as well as dealing with some of its
non-problem complaints (it doesn't like anchor (a) tags without either
an href, name, or id).
Running HTML proofer takes about 12 minutes on my system (with up to two
threads), during which it prints no text. Travis CI times out after 10
minutes of nothing being written to stdout, so this commit also adds a
background process the Makefile to print a line every minute while make
runs.
Remove right buttons and merge them in the menu
Switch to a centered design
Apply a consistent summary text for each page
Remove link to the Foundation in the main menu
Add a "Join Foundation" text in Participate
Add a link to the Foundation in the bottom page menu
Add a "Getting started" page with links to external merchants and exchanges directories.
Rewrite home page with weusecoins video and introductive links
Add useful contextual links on "Individuals", "Businesses" and "Developers" page
Re-design "Community" and "Resources" pages
Add links to the wiki, bitcoinmining.com, coindesk, thegenesisblock, letstalkbitcoin, usebitcoins.info and howtobuybitcoins.info
Re-design "Download" page with OS autodetect button
Improve "Secure your wallet" texts with a mention about exchanges
