Proxy: Single WebSocket connection

Proxy: Add keepalive directive to proxy to set MaxIdleConnsPerHost on transport

proxy: add Host header checking

dist/init/linux-sysvinit: execute setcap directly

`$(which setcap)` might evaluate to nothing,
and this way the error thrown will be more clear.
If setcap is not available on Debian/Ubuntu,
you can install the package `libcap2-bin`

* dist/init/linux-sysvinit: pass --oknodo for --start as well

* dist/init/linux-sysvinit: manually rm PIDFILE

Since start-stop-daemon --remove-pidfile is new and not present
everywhere.

dist/init/linux-sysvinit: fix minor typo in DAEMONOPTS

fix issue #993
Signed-off-by: Tw <tw19881113@gmail.com>

* improve rlimit usage

* fix windows build

* fix code style

added ip_hash load balancing

tls: fix TestStandaloneTLSTicketKeyRotation data race

==================
WARNING: DATA RACE
Write at 0x00c42049d300 by goroutine 26:
  github.com/mholt/caddy/caddytls.standaloneTLSTicketKeyRotation()
      /home/tw/golib/src/github.com/mholt/caddy/caddytls/crypto.go:230 +0x698

Previous read at 0x00c42049d300 by goroutine 25:
  github.com/mholt/caddy/caddytls.TestStandaloneTLSTicketKeyRotation()
      /home/tw/golib/src/github.com/mholt/caddy/caddytls/crypto_test.go:113 +0x413
  testing.tRunner()
      /home/tw/goroot/src/testing/testing.go:610 +0xc9

Goroutine 26 (running) created at:
  github.com/mholt/caddy/caddytls.TestStandaloneTLSTicketKeyRotation()
      /home/tw/golib/src/github.com/mholt/caddy/caddytls/crypto_test.go:101 +0x2a4
  testing.tRunner()
      /home/tw/goroot/src/testing/testing.go:610 +0xc9

Goroutine 25 (running) created at:
  testing.(*T).Run()
      /home/tw/goroot/src/testing/testing.go:646 +0x52f
  testing.RunTests.func1()
      /home/tw/goroot/src/testing/testing.go:793 +0xb9
  testing.tRunner()
      /home/tw/goroot/src/testing/testing.go:610 +0xc9
  testing.RunTests()
      /home/tw/goroot/src/testing/testing.go:799 +0x4b5
  testing.(*M).Run()
      /home/tw/goroot/src/testing/testing.go:743 +0x12f
  github.com/mholt/caddy/caddytls.TestMain()
      /home/tw/golib/src/github.com/mholt/caddy/caddytls/setup_test.go:27 +0x133
  main.main()
      github.com/mholt/caddy/caddytls/_test/_testmain.go:116 +0x1b1
==================
==================
WARNING: DATA RACE
Write at 0x00c4204aa6c0 by goroutine 26:
  github.com/mholt/caddy/caddytls.TestStandaloneTLSTicketKeyRotation.func2()
      /home/tw/golib/src/github.com/mholt/caddy/caddytls/crypto_test.go:93 +0x56
  github.com/mholt/caddy/caddytls.standaloneTLSTicketKeyRotation()
      /home/tw/golib/src/github.com/mholt/caddy/caddytls/crypto.go:233 +0x638

Previous read at 0x00c4204aa6c0 by goroutine 25:
  github.com/mholt/caddy/caddytls.TestStandaloneTLSTicketKeyRotation()
      /home/tw/golib/src/github.com/mholt/caddy/caddytls/crypto_test.go:108 +0x391
  testing.tRunner()
      /home/tw/goroot/src/testing/testing.go:610 +0xc9

Goroutine 26 (running) created at:
  github.com/mholt/caddy/caddytls.TestStandaloneTLSTicketKeyRotation()
      /home/tw/golib/src/github.com/mholt/caddy/caddytls/crypto_test.go:101 +0x2a4
  testing.tRunner()
      /home/tw/goroot/src/testing/testing.go:610 +0xc9

Goroutine 25 (running) created at:
  testing.(*T).Run()
      /home/tw/goroot/src/testing/testing.go:646 +0x52f
  testing.RunTests.func1()
      /home/tw/goroot/src/testing/testing.go:793 +0xb9
  testing.tRunner()
      /home/tw/goroot/src/testing/testing.go:610 +0xc9
  testing.RunTests()
      /home/tw/goroot/src/testing/testing.go:799 +0x4b5
  testing.(*M).Run()
      /home/tw/goroot/src/testing/testing.go:743 +0x12f
  github.com/mholt/caddy/caddytls.TestMain()
      /home/tw/golib/src/github.com/mholt/caddy/caddytls/setup_test.go:27 +0x133
  main.main()
      github.com/mholt/caddy/caddytls/_test/_testmain.go:116 +0x1b1
==================
Signed-off-by: Tw <tw19881113@gmail.com>

2 websocket connections are made instead of one

updated tests

fixed comment format

fixed formatting, minor logic fix

added newline to EOF

updated logic, fixed tests

added comment

updated formatting

updated test output

fixed typo

Re-enable HTTP/2 for Go 1.7.

dist/init/linux-sysvinit: caddy for SysVinit

In addition to `linux-upstart` and `linux-systemd`, I think this one
might be very useful too.

The script is based on [this script](https://git.devuan.org/fredg/stuffs/blob/master/caddy/init.d/caddy)
by @fredg, found via [Installation du serveur Caddy sous Devuan · Frédéric Galusik](http://galusik.xyz/installation-caddy-server-devuan/#démon:d7570338f345f168f3c50f22e7f8c47c).
I have modified it into an extended version myself, since I had the need for this.

redir: loading block arguments before parsing matcher

fix issue #977
Signed-off-by: Tw <tw19881113@gmail.com>

 * Since Go 1.7 HTTP/2 support is enabled only if TLSConfig.NextProtos
   includes the string "h2".
 * see mholt/caddy#975

Specify the reload signal in the upstart script

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