Shougo/neocomplcache — pull request #309 by graywh (2012-10-30 17:15:58+00:00)
Title: Don't echo an error when a message will do

`:echoerr` in a script gives users the impression something is wrong

```
Error detected while processing /path/to/file.vim:
line 1:
your message here
```

It's fine to use in maps because the script name and line number aren't displayed.