- Use Lucene's Directory to check whether index exist
- Split index exist check into two parts: the file part and the lucene directory part; catch exceptions thrown in the latter part.
- Replace reader.isDeleted with MultiFields.getLiveDocs
- Use IndexableField instead of Field

(Note: same changes a previous commit, different source file)
- Use Lucene's Directory to check whether index exists
- Replace reader.isDeleted with MultiFields.getLiveDocs
- Use IndexableField instead of Field
- Use TopDocs instead of Hits

(Note: same changes a previous commit, different source file)
- Use Lucene's Directory to check whether index exists
- Replace reader.isDeleted with MultiFields.getLiveDocs
- Use IndexableField instead of Field
- Use Lucene's Directory to check whether index exists
- Replace reader.isDeleted with MultiFields.getLiveDocs
- Use TopDocs instead of Hits
- Use CharArraySet instead of Hashtable
- remove unused imports.
- Reimplementation of finding terms with a prefix using RegexTermsEnum
- Use Lucene's Directory to check whether index exists
- Use File instead of String