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

discard remaining args for if block in redir.

fix rewrite if problem (skip remaining args)

* Initial concept for pluggable storage (sans tests and docs)

* Add TLS storage docs, test harness, and minor clean up from code review

* Fix issue with caddymain's temporary moveStorage

* Formatting improvement on struct array literal by removing struct name

* Pluggable storage changes:

* Change storage interface to persist all site or user data in one call
* Add lock/unlock calls for renewal and cert obtaining

* Key fields on composite literals

Changing refs from /usr/bin to /usr/local/bin

Thanks to @jaredfolkins for the feedback