Add BatList.filteri
Fix the return type of BatList.filteri
Add BatList.filteri_map
Merge pull request #450 from jpdeplaix/master

Add BatList.filteri
[text] improve element indexing in BatList's mli documentation
Add BatOption.some
Merge pull request #453 from jpdeplaix/master

Add BatOption.some
Explicitly remove preprocessed files instead of using "git clean" while executing "make clean"
Merge pull request #457 from jpdeplaix/master

Explicitly remove preprocessed files instead of using "git clean" while ...
fix a buggy test in for List.filteri_map
add @since to the documentation of Jacques-Pascal's recent additions
add a style check for '@since NEXT_RELEASE'
add Kahan summation (numerically-accurate sum of floats) to List,Array,Enum

This change is inspired by
  http://re-factor.blogspot.fr/2013/10/kahan-summation.html
itself coming from
  http://adereth.github.io/blog/2013/10/10/add-it-up/

I discovered in the process that Kahan Summation was already
implemented in Batteries, for Enum. In this case, the existing
overhead of accessing the next element apparently made it an option
for the 'fsum' function already.
some benchmarks of Kahan summation