TS-2343 Remove the --schema option from Traffic Manager
TS-2316: properly cherry-pick client header condition fix

This commit was cherry-picked with some errors:
    header_rewrite: fix for crash in client header condition

Pointy hat to: me (aivanov@)
Added TS-2343.
TS-2343 Remove --schema from docs, well the little that was there
TS-2340: fix TextLogObject log rolling
Merge branch 'master' of https://github.com/SaveTheRbtz/trafficserver
Runtimedir on Gentoo changed from /var/run to /run
TS-2348: Rename tstop to traffic_top
Make targets for creating releases+release candidates

What this does
==============

* remove the check for .svn: No longer necessary since we moved to git.

* for the `release` target we simply reuse asf-dist-sign, and
additionally create a signed tag of the same name.

* for the `rel-candidate` target, we add a variable `RC` to Makefile.am
with default value of 0. This can be overriden from outside by calling

    make release-candidate RC=14

NOTE: tags are created with `-f`. If a tag of the same name existed on
your system, it will be overwritten. This is considered a feature.

What this does *not* do
=======================

We are not pushing any tags upstream, or uploading any tarballs
anywhere. This is in the responsibility of the Release Manager.

Likewise, we do *not* bump the version in configure.ac
reliably recreate the same tar-ball from the same content

if the content of the tree is the same, we now create the same
tarballs with the same and sha1sums. We do this, by fixing the mtime of
all objects in the tarball to that of our ./configure.ac

In order for the content to be the same, we no longer rely on simply
calling $(MAKE) asf-dist-sign with a different version, but rather have
special targets, which simply inject the $(RC) variable.

These targets are entirely convinience wrappers for Release managers.

NOTE the GPG signature will always different, because it's a cryptographic
signature. In order to release 4.2.16-rc7 as 4.2.16, we can either call

    make release

or, simply rename the tar-ball. The content of the tar-ball will be the
same, regardless.
TS-2349: move traffic_cop to the cmd subdirectory
TS-2349: Move traffic_line to the cmd subdirectory
TS-2349: Move traffic_shell to the cmd subdirectory
TS-2349: update .gitignore

Ignore the command-line build artifacts in their new locations.
TS-2350: Enhancements to traffic_top
Revert "TS-2082: fix build with --enable-standalone-iocore"

This reverts commit 94215bf293d76d27a88a0fc9e35356321310fbf5.

This broke some cache regression tests and we are reverting it until
those can be addressed.
TS-2359: force tstop symlink

If you run "make install" a second time then "ln -s" will fail
because the symlink already exists. Autoconf doesn't have a test
for "ln -sf", so just remove the target beforehand.
TS-2361: improve regex_remap plugin loading semantics

The location of the regex_remap configuration is not well-defined
if it is a relative path. Either it will be found in the current
directory (which is undefined), or a hard-coded global directory
will be used.

This change always uses the absolute path if an absolute path is
provided. If a relative path is provided, then we load that relative
to the configured Traffic Server configuration directory.
TS-2360 Fix usage of TSMimeHdrFieldValueStringGet() in some plugins.

This also adds Sphinx docs for the TSMimeHdrFieldValueStringGet() and
family of APIs. Finally, it also adds a regression test for the -1
IDX argument.
Added TS-2360.