Add __repr__ for exception classes
Add __repr__ for exception classes

tdautc19841202/wechatpy,Dufy/wechatpy,cloverstd/wechatpy,hunter007/wechatpy,chenjiancan/wechatpy,hunter007/wechatpy,wechatpy/wechatpy,EaseCloud/wechatpy,messense/wechatpy,zhaoqz/wechatpy,Dufy/wechatpy,cloverstd/wechatpy,chenjiancan/wechatpy,navcat/wechatpy,tdautc19841202/wechatpy,Luckyseal/wechatpy,navcat/wechatpy,Luckyseal/wechatpy,mruse/wechatpy,EaseCloud/wechatpy,zhaoqz/wechatpy,mruse/wechatpy,tdautc19841202/wechatpy,zaihui/wechatpy,Luckyseal/wechatpy,zaihui/wechatpy,jxtech/wechatpy