Apache .htaccess to redirect www to naked domain and remove file extensions

.htaccess

ErrorDocument 404 /404.html
#
RewriteEngine on
RewriteBase /
#
# Redirect all www traffic to non-www (naked domain)
RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC]
RewriteRule ^(.*)$ http://%1/$1 [R=301,L]
#
#
# Replace html with your file extension, eg: php, htm, asp
RewriteCond %{REQUEST_FILENAME}.html -f
RewriteCond %{REQUEST_URI} !/$
RewriteRule (.*) $1\.html [L]
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.+)/$ /$1 [R=301,L]
#
#
# REDIRECTS
RedirectMatch 301 ^/about$ /about/business
RedirectMatch 301 ^/about/$ /about/business