Lucene2.3.1发布了
主要是修改了一些2.3.0版本的Bug，特别是当autoCommit=false的情况下以及多线程添加Document，有些字段打开了term-vector有些没有打都会对索引数据造成破坏
autoCommit 选项是从2.2.0版本就添加了，默认是true，我对这个参数还不是很理解，都是用的默认值true。所以没有碰到问题。
2.3.1版本没有包含任何新的功能，索引文件的格式也没有变化，完全兼容2.3.0版本。
官方鼓励所有使用2.3.0版本的应用尽快升级到2.3.1版本。
Bug fixes
1. LUCENE-1168: Fixed corruption cases when autoCommit=false and
documents have mixed term vectors (Suresh Guvvala via Mike
McCandless).
2. LUCENE-1171: Fixed some cases where OOM errors could cause
deadlock in IndexWriter (Mike McCandless).
3. LUCENE-1173: Fixed corruption case when autoCommit=false and bulk
merging of stored fields is used (Yonik via Mike McCandless).
4. LUCENE-1163: Fixed bug in CharArraySet.contains(char[] buffer, int
offset, int len) that was ignoring offset and thus giving the
wrong answer. (Thomas Peuss via Mike McCandless)
5. LUCENE-1177: Fix rare case where IndexWriter.optimize might do too
many merges at the end. (Mike McCandless)
6. LUCENE-1176: Fix corruption case when documents with no term
vector fields are added before documents with term vector fields.
(Mike McCandless)
7. LUCENE-1179: Fixed assert statement that was incorrectly
preventing Fields with empty-string field name from working.
(Sergey Kabashnyuk via Mike McCandless)
