major rewrite, reorg of blockpool + new features

- blockpool moves to its own package
- uses errs pkg for its own coded errors
- publicly settable config of params (time intervals and batchsizes)
- test helpers in subpackage
- optional TD in blocks used now to update peers chain info
- major improvement in algorithm
- fix fragility and sync/parallelisation bugs
- implement status for reporting on sync status (peers/hashes/blocks etc)
- several tests added and further corner cases covered

blockpool/test/util.go

@@ -0,0 +1,35 @@
+package test
+
+import (
+	"fmt"
+	"testing"
+	"time"
+)
+
+func CheckInt(name string, got int, expected int, t *testing.T) (err error) {
+	if got != expected {
+		t.Errorf("status for %v incorrect. expected %v, got %v", name, expected, got)
+		err = fmt.Errorf("")
+	}
+	return
+}
+
+func CheckDuration(name string, got time.Duration, expected time.Duration, t *testing.T) (err error) {
+	if got != expected {
+		t.Errorf("status for %v incorrect. expected %v, got %v", name, expected, got)
+		err = fmt.Errorf("")
+	}
+	return
+}
+
+func ArrayEq(a, b []int) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := range a {
+		if a[i] != b[i] {
+			return false
+		}
+	}
+	return true
+}