Implement SPLIT_BY_CHARACTERS.

This is much faster than regex.split if splitting by a single char,
or by a set of one-char delimiters.


[SVN r56191]

tools/build

@@ -1 +1 @@
-Subproject commit 427bd8e74d457efb2de27872fb589ce351689074
+Subproject commit f27340a9ca1e4c079df4a3df11d941bb2261f499