figments: command: rewrite command api to use Task instances instead of static functions

src/inputs/Serial.cpp

@@ -126,7 +126,7 @@ SerialInput::read()
 }
 
 void
-doHelp(Args& args, Print& out)
+SerialInput::doHelp(Args& args, Print& out)
 {
   out.println("Available commands:");
   auto sched = MainLoop::instance()->scheduler;
@@ -139,14 +139,13 @@ doHelp(Args& args, Print& out)
   out.println();
 }
 
-const std::vector<Command> serialCommands = {
-  {"help", doHelp}
-};
-
 const std::vector<Command>&
 SerialInput::commands() const
 {
-    return serialCommands;
+    static const std::vector<Command> _commands = {
+      {"help", &SerialInput::doHelp}
+    };
+    return _commands;
 }
 
 void
@@ -158,7 +157,7 @@ SerialInput::doCommand() {
   for(auto task : sched.tasks) {
     for(auto &command : task->commands()) {
       if (cmdName == command.name) {
-        command.func(args, m_logPrinter);
+        command.invoke(task, args, m_logPrinter);
         return;
       }
     }