完成适配器化改造，所有上报数据统一、接口调用等都改成通过不同消息源的适配器来完成，插件和消息源的耦合

commands/natural_language.py

@@ -1,15 +1,12 @@
-import os
-import importlib
-
 from command import CommandRegistry
 from commands import core
 from nl_processor import parse_potential_commands
-from little_shit import get_nl_processors_dir, get_fallback_command_after_nl_processors
+from little_shit import load_plugins, get_fallback_command_after_nl_processors
 from command import hub as cmdhub
 
 
 def _init():
-    _load_processors()
+    load_plugins('nl_processors')
 
 
 __registry__ = cr = CommandRegistry(init_func=_init)
@@ -41,13 +38,3 @@ def process(args_text, ctx_msg):
         core.echo('暂时无法理解你的意思。\n'
                   '由于自然语言识别还非常不完善，建议使用命令来精确控制我。\n'
                   '如需帮助请发送「使用帮助」。', ctx_msg)
-
-
-def _load_processors():
-    processor_mod_files = filter(
-        lambda filename: filename.endswith('.py') and not filename.startswith('_'),
-        os.listdir(get_nl_processors_dir())
-    )
-    command_mods = [os.path.splitext(file)[0] for file in processor_mod_files]
-    for mod_name in command_mods:
-        importlib.import_module('nl_processors.' + mod_name)