Fix evaluation of lit-words, lit-paths and set-paths

- Make inline evaluation of lit-word assigned to word return lit-word
- Make explicit evaluation of lit-path return path
- Make explicit evaluation of set-path trigger same error as set-word
- Fixes indentation style inconsistency in n-control.c

Fixes http://issue.cc/r3/1434 and http://issue.cc/r3/1883