z_file_get: hanging optional fileGet / wallet sites

[jaros1]

Problem with ZeroNet port closed and hanging optional fileGet. Now retrying fileGet operation 5 times with timeout 60 seconds. But long time to wait for a failed fileGet operation and critical for money transactions in wallet sites.

Fallback should be:

• other peers should help distribute money transaction files (-o = offline). But this is not working if ZeroNet port is closed. Other peers will hang too.
• should return some info to other peer about hanging fileGet operation -- in a encrypted wallet transaction file (optional or normal). Hanging peer may not have same problem with old ZeroNet port info. -- or maybe always use normal file for this type of notification. But still encrypted -- normal unencrypted file

[jaros1]

Add waiting_for_file notification and waiting_for_file callback to be used in fileGet timeout for optional files ... Many changes to MoneyNetworkAPI. Expects failed tests ...

[jaros1]

Closing. Is being tested in https://github.com/jaros1/Money-Network-W2/issues/41