重构框架，增加比赛功能

hydro/module/contest/acm.js

@@ -1,4 +1,5 @@
 module.exports = {
+    TEXT: 'ACM/ICPC',
     check: () => { },
     stat: (tdoc, journal) => {
         let naccept = {}, effective = {}, detail = [], accept = 0, time = 0;

hydro/module/contest/homework.js

@@ -1,5 +1,6 @@
 const { ValidationError } = require('../../error');
 module.exports = {
+    TEXT: 'Assignment',
     check(data) {
         if (!data.penalty_since) throw new ValidationError('penalty_since');
         if (data.penalty_since < data.begin_at) throw new ValidationError('penalty_since', 'begin_at');

hydro/module/contest/oi.js

@@ -1,4 +1,5 @@
 module.exports = {
+    TEXT: 'OI',
     check: () => { },
     stat: (tdoc, journal) => {
         let detail = {}, score = 0;