Fix FO XSL customisation layer to improve formatting - use widow and orphan control rather than "keep-together", make sure formatting is applied consistently across all elements, and allow code block to line wrap with hyphenation.

[SVN r51328]

doc/test/test.qbk

@@ -57,7 +57,7 @@ These should be syntax highlighted:
 
 [endsect]
 
-[section This should cause an error in PDF builds]
+[section Code With a Very Long Line]
 
 	template <class RealType> RealType inline foo(const RealType& a, const RealType& b, const RealType& c, const RealType& d, const RealType& e, const RealType& f, const RealType& g, const RealType& h){ return 0; }
 

tools/boostbook

@@ -1 +1 @@
-Subproject commit b55c27558f5b4a145564698ab6ee25eaefb2f11f
+Subproject commit eac7e37f0a343c67fbb86c7cf29323c519d2d3fd