[peermgr]
- Add request cache with tests
- Add requestCache to peermgr
- refactored peer manager tests
- Added blockInfo struct, to allow sorting on the blockIndex
- added helper methods for cache, pickItem, pickFirstItem, removeHash,
findHash and refactored tests
- renamed requestcache to blockcache
- refactored peer manager to use block cache for block requests *only*
- added blockCallPeer function to handle block requests only
- refactored onDisconnect to add back any pending peer requests that the
disconnected peer did not complete into the peer manager queue
[peermgr/server]
- Modify onBlock handler in server, to send peermgr a BlockInfo struct
[peermgr/syncmgr/server]
- Modified blockIndex in BlockInfo to be uint32 and not uint64
- RequestBlocks in syncmgr now takes an index along with the hash
- modified syncmgr code to pass index along with hash in all methods
