Fix #115: Speed up the link command.

 - Don't store intermediate `paths` variable; use pipes.
 - Use process substitution to speed up loops.
For #115: Update link file with newline test.

 - IFS manipulation did not appear to be doing anything helpful, so I
   removed it.
 - Linking files with a newline is not actually fixed, but the
   behavior did change slightly, so I updated the test.
Remove trailing whitespace.
Merge pull request #119 from dougborg/faster_link

Updates for a faster link command.