* Fix spork syncing issue in sporks tests
https://github.com/dashpay/dash/pull/2522 caused an issue with sporks syncing
in tests. The introduced time check in CMasternodeSync::ProcessTick causes
masternode sync to never start when mocktime is enabled, so this commit
disables mocktime for sporks.py.
Disabling mocktime however leads to fInitialDownload never becoming false
in CMasternodeSync::UpdatedBlockTip, so mnsync is never started. To fix
this, the tests now create a block before connecting the last node.
This however doesn't work because node1 will ignore the "getheaders" request
from node2 as it has not finished mnsync yet...so we also have to force
finish mnsync for node1.
* Also respond with getdata for announced sporks while in IBD
There was never a good reason to ignore spork announcements while in IBD.
At the same time, this poses the risk of missing out on sporks while in IBD.
This also fixes an issue in sporks testing, as nodes did not request for
announced sporks.
* Use wait_to_sync instead of custom loop
* CSporkManager class serialization
* Read/write sporks.dat file
* Move mapSporks into CSporkManager and serialize it
* fix GetSporkByHash
* spork tests
* add missed cs lock
* clear mapSporksByHash in CSporkManager::Clear
* use spork active rpc call to hide spork inner logic
* set small pause between rpc calls in cycles
