Build CLI interface for admin metadata table

[lintool]

Basic idea is to have a warcbase.meta table for storing collection-level metadata, e.g.,

• the Lucene FST for mapping URL <-> id
• record of data ingestion
• ARC/WARC
• etc.

This is a start: https://github.com/lintool/warcbase/blob/master/src/main/java/org/warcbase/WarcbaseAdmin.java