fish_config: Listen on both IPv6 and IPv4.

A subclass of TCPServer was created to deny any non-local connections and to
listen using an IPv6 socket.
Check effective credentials of socket peers

Fix for CVE-2014-2905.

Code for getpeereid() on non-BSD systems imported from the PostgreSQL
project under a BSD-style license.
use mktemp(1) to generate temporary file names

Fix for CVE-2014-2906.

Closes a race condition in funced which would allow execution of
arbitrary code; closes a race condition in psub which would allow
alternation of the data stream.

Note that `psub -f` does not work (#1040); a fix should be committed
separately for ease of maintenance.
Revert "Check effective credentials of socket peers"

This reverts commit 8412c867a501e3a68e55fef6215e86d3ac9f617b.

Just checking the credentials of the peer turns out to be insufficient.
See https://github.com/fish-shell/fish-shell/issues/1436.
Documentation update

Rework for Doxygen >1.8. Moved large parts of the documentation to a
simplified format, making use of Markdown enhancements and fixing bad
long options.
Added some clutter

Subllime and a few temporary files.
Removed dupes from gitignore
Merge branch 'master' into documentation-update

Conflicts:
	doc_src/history.txt
	doc_src/test.txt
Simplify styling
Merged in latest changes to docs and formatting tweaks

Addresses issue #1557 as well as fixing many typos, HTML errors and
inconsistencies. Also introduces automatic syntax colouring and enables
new documentation to be written in Markdown. TODO fix Tutorial.
Fixes lexicon filter pipes '|"
Style fix for sub-line comments
Lexicon filter: fix 'if' and 'for' special cases
Add lexicon filter to manpages.

 Fixed manpage 'NAME'. Under Doxygen 1.8, the output format has
changed, so the old sed script was leaving man pages with two titles.
Fix for CVE-2014-2905 - fishd restart required.

 - Use a secure path for sockets (some code used under license from
   tmux).
 - Provide the secure path in the environment as $__fish_runtime_dir.
 - Link the new path to the old path to ease migration from earlier
   versions.

Closes #1359.

After installing fish built from or after this commit, you MUST
terminate all running fishd processes (`killall fishd`, `pkill fishd`
or similar). Distributors are encouraged to do this from within their
packaging scripts. fishd will restart automatically, and no data should
be lost.
Further fixes to universal variable server socket management

- Change fishd_path to std::string
- Warn, rather than exiting with an error, if the universal variable
  server path is not available, and provide more useful advice.
- Export the new __fishd_runtime_dir variable.
Fix missed escaped '--' inside /fish block
Merge branch 'master' into documentation-update

Conflicts:
	doc_src/index.hdr.in -- UPDATED
	doc_src/license.hdr -- UPDATED
Update autoconf and README for Doxygen 1.8
Revert Xcode project

This reverts accidentally included files in commit
60b9f8db18b8889c3db864e443ee113d897bfe72.