Make "All Transactions" range consider future transactions

[hsoft]

From GS

The "All Transactions" range stops at now + ahead months, but it's a problem when adding transactions created in the future. It can also be frustrating to edit such transaction when in the "All Transactions" range because the transaction disappears.

Instead of stopping at now+ahead, moneyGuru should look if there's any manually edited transaction (as opposed to automatically created spawns, which can be infinite) past that date and extend the range if needed.

[hsoft]

(from [5ede904f5261]) [#322 state:fixed] Make all transaction go beyond today+ahead-months when needed.
https://bitbucket.org/hsoft/moneyguru/changeset/5ede904f5261/