Deprecate Plugin::HookCallFunction(), replace with HookFunctionCall()

This also changes the argument type of Func::operator() to zeek::Args*
to allow plugins to be able to alter function arguments in place as
was previously documented.

testing/btest/plugins/func-hook-plugin/src/Plugin.h

@@ -0,0 +1,27 @@
+
+#pragma once
+
+#include <plugin/Plugin.h>
+
+namespace plugin {
+namespace Demo_Hooks {
+
+class Plugin : public ::plugin::Plugin
+{
+protected:
+
+	std::pair<bool, IntrusivePtr<Val>> HookFunctionCall(const Func* func,
+	                                                    Frame* frame,
+	                                                    zeek::Args* args) override;
+
+	void MetaHookPre(HookType hook, const HookArgumentList& args) override;
+	void MetaHookPost(HookType hook, const HookArgumentList& args, HookArgument result) override;
+
+	// Overridden from plugin::Plugin.
+	plugin::Configuration Configure() override;
+};
+
+extern Plugin plugin;
+
+}
+}