Add new model to operate log (#3546)

* [Update] 添加一下model到operate log, [platform,remoteapppermission,changeauthplan,gatherusertask]

* [Bugfix] 修改了返回platform的几个位置，修改了command execution的url

* [Update] 优化ops task表结构，避免列表页查询几十次sql, 优化了基础的encryptjsonfield

* [Update] 修改adhoc 返回的become字段，避免密码泄露

* [Update] 修改变量名称

apps/assets/models/user.py

@@ -10,14 +10,13 @@ from django.db.models import Q
 from django.utils.translation import ugettext_lazy as _
 from django.core.validators import MinValueValidator, MaxValueValidator
 
-from common.utils import get_signer
+from common.utils import signer
 from .base import AssetUser
 from .asset import Asset
 
 
 __all__ = ['AdminUser', 'SystemUser']
 logger = logging.getLogger(__name__)
-signer = get_signer()
 
 
 class AdminUser(AssetUser):