If another ACME client is trying to solve a challenge for a name not
being served by Caddy on the same machine where Caddy is running, the
HTTP challenge will be consumed by Caddy rather than allowing the owner
to use the Caddyfile to proxy the challenge.

With this change, we only consume requests for HTTP challenges for
hostnames that we recognize. Before doing the challenge, we add the
name to a set, and when seeing if we should proxy the challenge, we
first check the path of course to see if it is an HTTP challenge;
if it is, we then check that set to see if the hostname is in the
set. Only if it is, do we consume it.

Otherwise, the request is treated like any other, allowing the owner
to configure a proxy for such requests to another ACME client.

* dist/init/linux-sysvinit: use kill -0 to test process status

* dist/init/linux-sysvinit: use service (as root) instead of /etc/init.d/

fix typo

* Rounding the latency in certain scenarios

* run gofmt

* Fix for stripping of 'Content-Disposition' and other headers from 'X-Accel-Redirect' redirect scripts.

* Added test case for header manipulation of redirect response.

* Add default "Restricted" realm to HTTP Basic auth

* Add tests for the Basic auth realm

* Allow just one TLS Protocol

* Fix typo

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