Merge the manual and script plugins (#3890)

* Start of combined manual/script plugin

* Return str from hooks.execute, not bytes

* finish manual/script rewrite

* delete old manual and script plugins

* manually specify we want chall.token

* use consistent quotes

* specify chall for uri

* s/script/hook

* fix spacing on instructions

* remove unneeded response argument

* make achall more helpful

* simplify perform

* remove old test files

* add start of manual_tests

* fix ParseTest.test_help

* stop using manual_test_mode in cli tests

* Revert "make achall more helpful"

This reverts commit 54b01cea30.

* use bad response/validation methods on achalls

* simplify perform and cleanup environment

* finish manual tests

* Add HTTP manual hook integration test

* add manual http scripts

* Add manual DNS script integration test

* remove references to the script plugin

* they're hooks, not scripts

* add --manual-public-ip-logging-ok to integration tests

* use --pref-chall for dns integration

* does dns work?

* validate hooks

* test hook validation

* Revert "does dns work?"

This reverts commit 1224cc2961.

* busy wait in manual-http-auth

* remove DNS script test for now

* Fix challenge prefix and add trailing .

* Add comment about universal_newlines

* Fix typo from 0464ba2c4

* fix nits and typos

* Generalize HookCOmmandNotFound error

* Add verify_exe_exists

* Don't duplicate code in hooks.py

* Revert changes to hooks.py

* Use consistent hook error messages

certbot/plugins/selection.py

@@ -133,7 +133,7 @@ def choose_plugin(prepared, question):
         else:
             return None
 
-noninstaller_plugins = ["webroot", "manual", "standalone", "script"]
+noninstaller_plugins = ["webroot", "manual", "standalone"]
 
 def record_chosen_plugins(config, plugins, auth, inst):
     "Update the config entries to reflect the plugins we actually selected."
@@ -238,8 +238,6 @@ def cli_plugin_requests(config):
         req_auth = set_configurator(req_auth, "webroot")
     if config.manual:
         req_auth = set_configurator(req_auth, "manual")
-    if config.script:
-        req_auth = set_configurator(req_auth, "script")
     logger.debug("Requested authenticator %s and installer %s", req_auth, req_inst)
     return req_auth, req_inst