(#21258) Update link to LSB exit code documentation

Link to linuxfoundation.org, as the content had moved and the
refspecs.freestandards.org domain can no longer be resolved by DNS.

Also updated to link to latest LSB release (4.1.0).
(#22891) Use the most preferred supported format

Previously the code had assumed that the order of the supported formats
didn't mean anything. However, the preferred_serialization_format, and
other factors, meant that the order really does matter. This makes the
selected format, when the Accept header is */* be the most preferred,
supported format.
(Maint) Refactor retrieving the indirection in http handler

Pass the full indirection object into do_* methods instead of just the name.
This is a better access point for getting what these methods need and reduces
duplication.
(#22893) Make handler check whether remote requests are allowed

The http handler will check whether an indirection allows remote requests
before performing any operations.
(#22893) Disable remote requests for key termini

These don't make sense to use remotely since they manage private keys.
(Maint) Remove no-op rescue clause
Merge pull request #2000 from zaphod42/issue/master/22891-respect-preferred_serialization_format_for_any_media_type

(#22891) Use the most preferred supported format
Merge pull request #2003 from pcarlisle/ticket/22893-control-remote-requests

Ticket/22893 control remote requests
Merge pull request #1989 from 3flex/fix/master/21258-stale-LSB-links

(#21258) Update link to LSB exit code documentation
Merge branch 'master' of https://github.com/puppetlabs/puppet