Remove old out-dated BIND10 content.

Mention some more Kea tools and minor rewording.

Note that the brief sections on starting and stopping and managing
the software are now gone.
fix typo
misc improvements:

fixed install directories

mention openssl

fix url for tarball download (note doesn't exist at time of this
commit)

add some more common configure switches

change kea config "BIND10" to "BUNDY"

fix some paths from bind10 to kea.

minor rewording
change pool: to "pool": in examples

(wlodek told me)
fix typos in configurations

missing " quote for json configuration
misc improvements:

BUNDY instead of BIND10

remove old comment

shell instead of bash

fix pointer to examples in installed location instead of source tree
install ddns example configurations

(I also fixed docs in different commit to
fix pointer to examples in installed location instead of source tree.)

Okayed ("seems ok") via jabber.
use entity &mdash; instead of - dash
just keep statement as one sentence

versus splitting sentence with example in  middle.
This is just my style preference.
trivial typo fix in comment
Add the RFC titles

and remove comment about "drafts" since none here

fix one grammar plural mistake

for titles of this section mention DCHP or DHCPv6
fix typo for keactrl name
just keep sentence together

versus splitting sentence with example in  middle.
This is just my style preference.

While doing this fix the explanation for enabling mysql and postgres
as previously it appeared to imply that you had to specify
the path to the config script (but first example didn't follow what
was stated).
change BIND 10 references to Kea.
change BIND 10 reference to Kea
remove my years old comments (no content change)
fix script that creates log messages HTML to say Kea instead of BIND 10
modify warning about abuse of the dhcp-ddns server

discussed little on jabber.
I opened a new ticket to fix code to at #3514
Get rid of errant ) close parenthesis.
be clear that past BIND 10 sponsors were in the past

and not current.

Also mention ISC is the maintainer.