Wave: added new preprocessing hook: emit_line_directive, fixed a couple related problems, added new example

[SVN r60818]

libs/wave

@@ -1 +1 @@
-Subproject commit 75119781b0f920efb92af9376395556e6d6490c7
+Subproject commit 2d58e13c57f2a0c6ee2e163993fb7dd8e58a42e1