Merge :run-userscripts into :spawn.

:run-userscripts is now marked as deprecated, and :spawn has a new
-u/--userscript option instead.

Closes #448.

doc/help/commands.asciidoc

@@ -32,7 +32,6 @@
 |<<repeat,repeat>>|Repeat a given command.
 |<<report,report>>|Report a bug in qutebrowser.
 |<<restart,restart>>|Restart qutebrowser while keeping existing tabs open.
-|<<run-userscript,run-userscript>>|Run an userscript given as argument.
 |<<save,save>>|Save the config file.
 |<<search,search>>|Search for a text on the current page.
 |<<set,set>>|Set an option.
@@ -351,16 +350,6 @@ Report a bug in qutebrowser.
 === restart
 Restart qutebrowser while keeping existing tabs open.
 
-[[run-userscript]]
-=== run-userscript
-Syntax: +:run-userscript 'cmd' ['args' ['args' ...]]+
-
-Run an userscript given as argument.
-
-==== positional arguments
-* +'cmd'+: The userscript to run.
-* +'args'+: Arguments to pass to the userscript.
-
 [[save]]
 === save
 Save the config file.
@@ -404,7 +393,7 @@ Preset the statusbar to some text.
 
 [[spawn]]
 === spawn
-Syntax: +:spawn 'args' ['args' ...]+
+Syntax: +:spawn [*--userscript*] 'args' ['args' ...]+
 
 Spawn a command in a shell.
 
@@ -413,6 +402,9 @@ Note the {url} variable which gets replaced by the current URL might be useful h
 ==== positional arguments
 * +'args'+: The commandline to execute.
 
+==== optional arguments
+* +*-u*+, +*--userscript*+: Run the command as an userscript.
+
 [[stop]]
 === stop
 Stop loading in the current/[count]th tab.

qutebrowser/browser/commands.py

@@ -795,7 +795,7 @@ class CommandDispatcher:
             tabbed_browser.setUpdatesEnabled(True)
 
     @cmdutils.register(instance='command-dispatcher', scope='window')
-    def spawn(self, *args):
+    def spawn(self, userscript=False, *args):
         """Spawn a command in a shell.
 
         Note the {url} variable which gets replaced by the current URL might be
@@ -807,9 +807,17 @@ class CommandDispatcher:
         don't care about the process anymore as soon as it's spawned.
 
         Args:
+            userscript: Run the command as an userscript.
             *args: The commandline to execute.
         """
-        log.procs.debug("Executing: {}".format(args))
+        log.procs.debug("Executing: {}, userscript={}".format(
+            args, userscript))
+        if userscript:
+            if len(args) > 1:
+                self.run_userscript(args[0], args[1:])
+            else:
+                self.run_userscript(args[0])
+        else:
             try:
                 subprocess.Popen(args)
             except OSError as e:
@@ -821,7 +829,8 @@ class CommandDispatcher:
         """Open main startpage in current tab."""
         self.openurl(config.get('general', 'startpage')[0])
 
-    @cmdutils.register(instance='command-dispatcher', scope='window')
+    @cmdutils.register(instance='command-dispatcher', scope='window',
+                       deprecated='Use :spawn --userscript instead!')
     def run_userscript(self, cmd, *args: {'nargs': '*'}):
         """Run an userscript given as argument.