ADD increase activity function
	修改:         main/application/controllers/act_add.php
	ADD a function of increase activity
	修改:         main/application/libraries/Secure.php
	ADD a function to judge datetime format
	修改:         main/application/models/act_model.php
	ADD a series of activity database interactive function
	修改:         main/application/models/role_model.php
	修改:         main/application/models/section_model.php
	修改:         main/application/models/user_model.php
	UPDATE the algorithm of judge data existed
	修改:         main/application/views/act_add_view.php
	ADD the view of 'act_add.php'