BatSubstring.contains with doc + inline tests
added BatSubstring.equal
Merge pull request #342 from rgrinberg/substring_fix

BatSubstring.equal and BatSubstring.contains
Merge pull request #343 from madroach/master

as requested, add comments to Num.of_float testcase
BatSubstring.iteri
fixed i starting at offset. added tests to runner
Merge pull request #345 from rgrinberg/substring

BatSubstring.iteri
Add unicode libs to API docs
Avoid useless allocation in BatSplay.cfind

Probably not a huge gain, though
Merge pull request #350 from rixed/avoid-alloc

Avoid useless allocation in BatSplay.cfind
Don't copy array for BatArray.backwards enum clone

This will make it faster and enable value sharing.
Without sharing a change to the original array would be visible in the
original backwards enum, but not in its clone. This certainly is not the
expected behaviour.

See commit 8944b0d30b5d062e2f01f5bd9e73e5a9718c5a51