* httpserver/all: Clean up and standardize request URL handling

The HTTP server now always creates a context value on the request which
is a copy of the request's URL struct. It should not be modified by
middlewares, but it is safe to get the value out of the request and make
changes to it locally-scoped. Thus, the value in the context always
stores the original request URL information as it was received. Any
rewrites that happen will be to the request's URL field directly.

The HTTP server no longer cleans /sanitizes the request URL. It made too
many strong assumptions and ended up making a lot of middleware more
complicated, including upstream proxying (and fastcgi). To alleviate
this complexity, we no longer change the request URL. Middlewares are
responsible to access the disk safely by using http.Dir or, if not
actually opening files, they can use httpserver.SafePath().

I'm hoping this will address issues with #1624, #1584, #1582, and others.

* staticfiles: Fix test on Windows

@abiosoft: I still can't figure out exactly what this is for. 😅

* Use (potentially) changed URL for browse redirects, as before

* Use filepath.ToSlash, clean up a couple proxy test cases

* Oops, fix variable name

internal: inherit original ResponseWriter's interfaces

Signed-off-by: Tw <tw19881113@gmail.com>

* Raise syntax error if no '/' prefix to rewrite. Added Tests

* fix case where to keyword is used.

* Fixed spelling issue

* Changes to use Errf rather than new Err function

* Remove new RewritePathErr Function

Bugfix for issue #1628 where `Caddyfile` is not being hidden correctly

Added test case to check if Caddyfile is added to HiddenFiles correctly.

proxy: recognize client's cancellation

Context: add Push action

lint fixes

fix issue #1589
Signed-off-by: Tw <tw19881113@gmail.com>

Signed-off-by: Tw <tw19881113@gmail.com>

* update to match same paths as systemd

* update to match new launchd plist

* generated from scratch with LaunchControl, flawless

Had some issues with the previous go and found LaunchControl which made it easy to generate a perfectly correct launchd conf

* Update README.md

* Strip brackets in IsInternal if no port, allow loopback for CA URLs

* Fix a mistake

* Improve the trim

* Fix comment

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

* gzip: pool gzip.Writer to reduce allocation
Signed-off-by: Tw <tw19881113@gmail.com>

Also disable some tests on context.Hostname because they're not portable

proxy: take original URL path into account when remove prefix ("without")

fix issue #1604
Signed-off-by: Tw <tw19881113@gmail.com>

httpserver: Don't close stdout or stderr when closing logs (fix #1471)

* Disable warning for insecure CA if located on private network.
 * Add IsPrivateNetwork function
 * Add tests
Signed-off-by: Jonas Östanbäck <jonas.ostanback@gmail.com>

* Add more testcases
Signed-off-by: Jonas Östanbäck <jonas.ostanback@gmail.com>

* Rename IsPrivateNetwork -> IsInternal
Signed-off-by: Jonas Östanbäck <jonas.ostanback@gmail.com>

templates: Add Hostname template action

This adds the ability to display the remote hostname
of the visitors IP with template actions.

template: add test for custom function

Signed-off-by: Tw <tw19881113@gmail.com>

template: support custom functions

Signed-off-by: Tw <tw19881113@gmail.com>

proxy: use untouched URL for concatenating