Clean up some pa_llist remanents

A little bit of pa_llist was found in myocamlbuild and testsuite/_tags
Fix #363: generalize Set.map's type, add op_map

op_map covers the special case that the mapping function is order preserving and the tree doesn't need to be rebuilt.  Otherwise map rebuilds the whole tree
BatText: remove deprecated Invalid_rope exception
Merge pull request #365 from kerneis/remove-invalid-rope

BatText: remove deprecated Invalid_rope exception
batOption: addition of default_delayed and map_default_delayed.

  val default_delayed : (unit -> 'a) -> 'a option -> 'a
  val map_default_delayed : ('a -> 'b) -> (unit -> 'b) -> 'a option -> 'b
Fix #368: Enum.concat had wrong clone implementation
Fix #367: Add Set.find operation to match stdlib
Reformat all source code in src/ using ocp-indent; whitespace only changes
Fix bug in set.find order
Expose BatSet.find, add tests
BatText: add test for explode and implode
Fix list order in BatText.explode

The list of characters was output in reversed order.
fix BatFloat.round corner case on predecessor of 0.5
BatBitSet: Fix last element access
Merge pull request #369 from zakki/master

Fix batBitSet
Add empty line around macro
Merge branch 'master' into for-js

Conflicts:
	myocamlbuild.ml
	src/batBase64.ml
	src/batBig_int.ml
	src/batBigarray.mli
	src/batBool.ml
	src/batCache.ml
	src/batCache.mli
	src/batComplex.ml
	src/batDeque.ml
	src/batDeque.mli
	src/batDigest.mli
	src/batDllist.mli
	src/batDynArray.mli
	src/batFile.mli
	src/batFingerTree.mli
	src/batGc.mli
	src/batGenlex.ml
	src/batGlobal.ml
	src/batHashtbl.mlv
	src/batISet.ml
	src/batInnerIO.mli
	src/batInnerWeaktbl.mli
	src/batInt32.mli
	src/batInt64.mli
	src/batLexing.mli
	src/batLogger.ml
	src/batLogger.mli
	src/batMap.mli
	src/batMultiMap.mli
	src/batMultiPMap.mli
	src/batNum.ml
	src/batOptParse.ml
	src/batOptParse.mli
	src/batPervasives.ml
	src/batPervasives.mliv
	src/batPrintexc.mli
	src/batRMutex.ml
	src/batRMutex.mli
	src/batSet.ml
	src/batSplay.mli
	src/batStream.ml
	src/batStream.mli
	src/batString.ml
	src/batString.mli
	src/batSubstring.mli
	src/batSys.mli
	src/batText.mli
	src/batUnit.ml
	src/batUnix.ml
	src/batUnix.mliv
	src/batUref.ml
	src/batUref.mli
	src/batteriesPrint.ml