Rank matches where the pattern matches the start of a path component higher

Calculate the number of path-component prefix matches for each query
match and rank query matches with more prefix matches higher.

eg. Given the query 'foo' and two candidates:
   1) /path/to/foo
   2) /path/to/somethingfoo

This would rank 1) above 2)
Add a setup.sh script to simplify install of rd and setup of the daemon to run at login
Clarify the setup steps on Ubuntu for setting up Go