Repair missed Snapshot.getHeader
Fixed HEAP serialization

Added serialization test
Updated serialization chunk size - large size works stable on sockets
connection.
Repaire missed API for node-inspector tests

Remove error throwing for not found snapshots and profiles.
Repaired startTrackingHeapObjects.
Repaired stopTrackingHeapObjects.
Repaired getHeapStats.
Fix binaries for node-inspector

CPU sampling enabled by default.
HEAP sample changed from object to id number
Version changed to 5.1.0