Added List.const
Added List.sharedPrefix
Added File.relativeTo, closes #19
Merge pull request #65 from fommil/master

close #64 (coverage reports) and work toward #11 (cross builds)
Make file.children null safe, closes #66
Added String.sharedPrefix
Added Either <=> Try <= Option, closes #10
Increate coverage of XMappedNumeric
100% coverage should be enough for anybody !
Added Predicate.ifSome, closes #29
Renamed package object to multiMap, closes #67
publish close #68