TBILLMATURIOTY Type to enums.Reorg, netCashInBase to AssetSummary

[pstinner]

The 3rd change, PutCall enum in this commit I don't remember, but if I comment that line, then it gives an error:

ImportError: cannot import name 'PutCall' from 'ibflex' (...\lib\site-packages\ibflex_init_.py)