replace errors.go with github.com/pkg/errors (2/2) (#3890)

* init of (2/2) common errors

* Remove instances of cmn.Error (2/2)

- Replace usage of cmnError and errorWrap
- ref #3862

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

* comment wording

* simplify IsErrXXX functions

* log panic along with stopping the MConnection

privval/utils_test.go

@@ -1,15 +1,13 @@
 package privval
 
 import (
-	"fmt"
 	"testing"
 
+	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
-
-	cmn "github.com/tendermint/tendermint/libs/common"
 )
 
 func TestIsConnTimeoutForNonTimeoutErrors(t *testing.T) {
-	assert.False(t, IsConnTimeout(cmn.ErrorWrap(ErrDialRetryMax, "max retries exceeded")))
-	assert.False(t, IsConnTimeout(fmt.Errorf("completely irrelevant error")))
+	assert.False(t, IsConnTimeout(errors.Wrap(ErrDialRetryMax, "max retries exceeded")))
+	assert.False(t, IsConnTimeout(errors.New("completely irrelevant error")))
 }