Don't allow to set hints.selectors in autoconfig.yml

Also, set all settings temporarily for end2end tests.
This allows us to set things which aren't settable in autoconfig.yml.

doc/help/settings.asciidoc

@@ -2581,6 +2581,8 @@ CSS selectors used to determine which elements on a page should have hints.
 
 This setting supports URL patterns.
 
+This setting can only be set in config.py.
+
 Type: <<types,Dict>>
 
 Default: 

qutebrowser/config/configdata.yml

@@ -1163,6 +1163,7 @@ hints.scatter:
     Ignored for number hints.
 
 hints.selectors:
+  no_autoconfig: true
   default:
     all:
       - 'a'

tests/end2end/features/hints.feature

@@ -202,14 +202,14 @@ Feature: Using hints
 
     Scenario: Custom hint group with URL pattern
         When I open data/hints/custom_group.html
-        And I run :set -u *://*/data/hints/custom_group.html hints.selectors '{"custom": [".clickable"]}'
+        And I run :set -tu *://*/data/hints/custom_group.html hints.selectors '{"custom": [".clickable"]}'
         And I hint with args "custom" and follow a
         Then the javascript message "beep!" should be logged
 
     Scenario: Fallback to global value with URL pattern set
         When I open data/hints/custom_group.html
         And I set hints.selectors to {"custom":[".clickable"]}
-        And I run :set -u *://*/data/hints/custom_group.html hints.selectors '{"other": [".other"]}'
+        And I run :set -tu *://*/data/hints/custom_group.html hints.selectors '{"other": [".other"]}'
         And I hint with args "custom" and follow a
         Then the javascript message "beep!" should be logged
 

tests/end2end/features/javascript.feature

@@ -168,7 +168,7 @@ Feature: Javascript stuff
 
     Scenario: Per-URL localstorage setting
         When I set content.local_storage to false
-        And I run :set -u http://localhost:*/data2/* content.local_storage true
+        And I run :set -tu http://localhost:*/data2/* content.local_storage true
         And I open data/javascript/localstorage.html
         And I wait for "[*] local storage is not working" in the log
         And I open data2/javascript/localstorage.html
@@ -176,7 +176,7 @@ Feature: Javascript stuff
 
     Scenario: Per-URL JavaScript setting
         When I set content.javascript.enabled to false
-        And I run :set -u http://localhost:*/data2/* content.javascript.enabled true
+        And I run :set -tu http://localhost:*/data2/* content.javascript.enabled true
         And I open data2/javascript/enabled.html
         And I wait for "[*] JavaScript is enabled" in the log
         And I open data/javascript/enabled.html

tests/end2end/fixtures/quteprocess.py

@@ -667,7 +667,7 @@ class QuteProc(testprocess.Process):
         # \ and " in a value should be treated literally, so escape them
         value = value.replace('\\', r'\\')
         value = value.replace('"', '\\"')
-        self.send_cmd(':set "{}" "{}"'.format(option, value), escape=False)
+        self.send_cmd(':set -t "{}" "{}"'.format(option, value), escape=False)
         self.wait_for(category='config', message='Config option changed: *')
 
     @contextlib.contextmanager