Change position of locale directive

First, great job on the 0.9 release! It seems caddy's path lead into a bright future. Thanks also for including the locale plugin.

Trying it, I've figured out, that there might be a problem with the order of the directives. In the typical use case, the result of the locale detection might be used in the `rewrite` and `log` plugin. If I'm not mistaken, it makes sense to put the `locale` directive before those.

Register ratelimit

This reverts commit 9ea05919, reversing
changes made to 2125ae5f.

minor condition keyword check refactor

proxy: fix hyphen issue when parsing target

HTTP Headers

fix issue #948
Signed-off-by: Tw <tw19881113@gmail.com>

add a test to ensure this works.

* proxy: add benchmark
Signed-off-by: Tw <tw19881113@gmail.com>

* replacer: prepare lazily

update issue#939

benchmark            old ns/op     new ns/op     delta
BenchmarkProxy-4     83865         72544         -13.50%
Signed-off-by: Tw <tw19881113@gmail.com>

* proxy: use buffer pool to avoid temporary allocation
Signed-off-by: Tw <tw19881113@gmail.com>

Update readme contributing section

* Allow for UDP servers

Extend the Server interface with ServePacket and ListenPacket - this is
in the same vein as the net package.

Plumb the packetconn through the start and restart phases.

Rename RestartPair to RestartTriple as it now also contains a Packet.
Not that these can now be nil, so we need to check for that when
restarting.

* Update the documentation

fix: import should always be relative to current file directory

fix transparent host header #916

* import should get absolute path before glob

* fix test: import should get absolute path before glob

* try to fix test on windows

* use complete path as the dispenser filename

* fix caddyfile test

* Prototype middleware Config

* Refactors

* Minor refactors