Optimized Data Structure

Optimized Data Structure to read extra informations for a class. These
informations include: ‘Held With’, ‘Topic’ and ‘Reserve’.
-Add CClass-TBI
-Modified CClass attribute note
-Modified readClasses: can read extra informations
-Test output information in logging.info
-Add Error Page for url error
-Delete Comment: Database code
-Minor spelling error: time_data -> time_date
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完善了数据结构，增加了CClass-TBI类，可以读取单个课程的额外信息，包括‘Held With’, ‘Topic’ 和 ‘Reserve’.