read-ns-form: rethrow FileNotFoundExceptions more informatively

[vemv]

• read-ns-form: rethrow FileNotFoundExceptions more informatively
  • Simply rethrows this exception if it arises with particularly useful wording and ex-data. Otherwise logic isn't changed at all.
  • Fixes move form refactoring doesn't follow symlinks #142
    • (That issue has nothing actionable refactor-nrepl side, it's a clj-refactor.el bug)
• Bump Eastwood

[vemv]

DRYed out the duplication across the two arities of read-ns-form.

Took care of making them 100% equivalent. The key is here:

(if dialect
  {:read-cond :allow :features #{dialect}}
  nil)

The nil value makes readers/indexing-push-back-reader behave exactly as if it hadn't received this argument at all.