A couple of fixes: SQLite tuning and pings

[vyzo]

SQLite tuning:

• tune concurrent write performance by disabling the connection pooling (lock contention!) and enabling Write-Ahead Logging

/ping protocol:

• Ensure there is a connection to the directory before trying to open a stream
• Add a 30s timeout to /ping; one day it may become a request parameter (and be common with other requests that access remote resources)

[yusefnapora]

👍 nice