apcupsd - small fix and update

- Fix rcfile for removing all types of lock files
- Add an information for email notifications

Could you rebuild the binaries for 2.1, please? On 2.2 it's already built. 
On a next PR I will bump version.

Thanks.



You could replace this for by a single command:
```
rm -f ${lockfile}/*LCK* 2>/dev/null
```

Also note that in shell you should use ${VAR}, the syntax being used is from PHP {$VAR}