driver: Don't waste resources setting/being-notified up in progress handler if context cannot be canceled

driver: Don't waste resources setting/being-notified up in progress handler if context cannot be canceled

Please see https://github.com/mattn/go-sqlite3/pull/530 for similar
change. Here it is not additional goroutine but a callback setup which
will be called ever 100 ops. We can avoid that if we know that ctx
cannot be canceled.

Caveat: it will not be possible to retry on SQLITE_BUSY.

Add working cgo defaults for FreeBSD (#7)

To be fixed: cgocheck & panic

Still missing: StmtExecContext and StmtQueryContext

To be continued

It does not seem to be specify but it fails at runtime.