Fixes for the linter, massive godoc update

context.go

@@ -0,0 +1,13 @@
+package main
+
+// ExitFuncKey is the key name of the exit function in context
+const ExitFuncKey = contextKey("exitFunc")
+
+// CancelFuncKey is the key name of the cancel function in context
+const CancelFuncKey = contextKey("cancelFunc")
+
+type contextKey string
+
+func (c contextKey) String() string {
+	return "s5cmd context key " + string(c)
+}

error.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 )
 
+// IsRetryableError returns if an error (probably awserr) is retryable, along with an error code
 func IsRetryableError(err error) (string, bool) {
 	if err != nil {
 		if awsErr, ok := err.(awserr.Error); ok {
@@ -36,6 +37,7 @@ func IsRetryableError(err error) (string, bool) {
 	return "", false
 }
 
+// CleanupError converts multiline error messages generated by aws-sdk-go into a single line
 func CleanupError(err error) (s string) {
 	s = strings.Replace(err.Error(), "\n", " ", -1)
 	s = strings.Replace(s, "\t", " ", -1)