Added phrecon.py (v3.0 python port with sqlite)
Fixed SNP reconstruct query (parameterized subquery strainid) in phrecon.py
Changed phrecon.py REF rebuild query with correct outer join logic.  Added pragmas for dbfile option.
Version 3.1 of phrecon.py - Reverted to dictionary imple.

Reverted from database driven to in-memory dictionary-based processing.
phrecon.py - Removed collections and multiprocessign import.

This is the final version of the initial port from perl (phrecon version 2.1)
to python.

NOTE: This does NOT use sqlite3 and, like the perl version, is
dictionary-based.
phrecon.py - Updated version history comments to be accurate.