Split paths into watched and relative

[e2]

Make every path used in Listen separate from work directory.

This is so ultimately watched directories are truly separate and contain their own config.

Implications:

• every directory could have it's own Record
• Record uses up less memory
• silencer can work more reliably (not "hack" to turn path into relative to watched dir)
• TCP message format is incompatible
• Record distinguishes files from dirs based on existence of :mtime field
• Listener config no longer has to be passed down to adapter
• Silencer no longer includes Celluloid overhead
• in the future, Record could be turned on/off for specific directories
• much cleaner debug/output possible (only relative paths)

[coveralls]

Coverage increased (+0.61%) when pulling 94ea2cf on split_paths_into_watched_and_relative into 18d5860 on master.

[coveralls]

Coverage increased (+0.7%) when pulling 3036c5f on split_paths_into_watched_and_relative into 18d5860 on master.