Fix --watch flag not working on Linux.

[daedlock]

Two issues:

1. Event filtering too strict for Linux - inotify reports Data(Any) instead of Data(Content), and
   atomic file replacements (how cargo build works) emit Name(To)/Name(Both) events. Added these
   patterns to the match.
2. Watch thread dying silently - Runbook execution was panicking, killing the watch thread.
   Wrapped in catch_unwind to keep the thread alive.

Fixes #362

[MicaiahReid]

Awesome, thanks @daedlock!!

[lgalabru]

Awesome,thanks 🦾