New -inverse flag, fixed crash-recovery and various fixes

[Dimagog]

New feature:

• -inverse flag changes the sign of amount found in .csv to the opposite. This is to support some Credit Cards (e.g. Discover) that report spending as positive values.

Crash-recovery fixed: Completely reworked interaction with Bolt DB. Now it actually helps to recover previously reconciled transactions after a crash by recovering assigned account and marking them "Done".

Other Fixes:

• Single-key keyboard entry support for Windows (was completely broken)
• Stable-sort of imported transaction to avoid reordering of same-day transactions. Also fixed byTime.Less to accommodate Stable-sort
• Remove account we are importing from, from classes during tf-idf model training
• Fixed topHits for cases when there are less than 5 accounts
• Start transaction indices from 1 (not 0) when displaying them
• Skipping transaction unmarks it as cleared