Fix BatMutex.DebugMutex.id is always 0.
added range
added unit tests for range
added ocamldoc for range
better ocamldoc
added split_opt wherever there is split
added split_opt wherever there is split
unit test for split_opt
added split_lt and split_le
implementations for split_lt and split_le
unit tests for split_lt and split_le
easier to read tests with less test variables and more explicit lists
use pred and succ instead of (-) and (+)
Merge pull request #426 from zakki/debug-mutex-id

Fix BatMutex.DebugMutex.id is always 0.
Merge pull request #428 from UnixJunkie/batlist_range

range for BatList
Merge pull request #429 from UnixJunkie/batset_split_opt

add BatSet.split_opt
Merge pull request #430 from UnixJunkie/batset_split_lt_split_le

Add BatSet.{split_lt,split_le}