remove pid- & logfiles on `exit` and `stop`

fixes #327
don't remove log files
wrapped fs.unlinkSync in try-catch-block
Fix uids mistakenly taken for an id
use process.env.USERPROFILE as alternative to process.env.HOME (for windows)
Use `path` option as forever root if given.

Fixes #258
Support exit signal customization (comes from another commit to forever-monitor)
Add timestamp support to forever log

With `forever set timestamp true` the log will contain timestamps,
fixes #309 and #314
Update package.json

Use the latest version of forever-monitor.
This would consider the "killSignal" property in "options".
modified package name