Workaround for bjam scanner bug that captures trailing newlines.

Added docutils-cmd feature that allows the command to be overridden.


[SVN r36492]

tools/build

@@ -1 +1 @@
-Subproject commit d6f1461e2d729661e6619a47ce33fca1b134e138
+Subproject commit 2e0d7d416ddd64ab00591fb574e5574e79cfa517