Fix issues 1259 and 1433 (\breakDynamicSpan and a spanner's style=#'none over a line break) (issue4630070)

[n . puttock]

Hi Reinhold,

I'm afraid this fails `make check'.
dynamics-alignment-no-line-linebreak.ly weirdly works directly without a
hitch, but crashes under test conditions:

Processing `./1e/lily-b9dc92b9.ly'
Parsing...
Renaming input to: `dynamics-alignment-no-line-linebreak.ly'
Interpreting music...
Preprocessing graphical objects...
Calculating line breaks...
Drawing systems...
Writing header field `texidoc' to `./1e/lily-b9dc92b9.texidoc'...
Writing ./1e/lily-b9dc92b9-1.signature
Writing ./1e/lily-b9dc92b9-2.signatureUnbound variable: open-file
Unbound variable: open-file
ERROR: In procedure ly_grob_extent:
ERROR: Wrong type argument in position 2 (expecting common refpoint):
#<Grob System >

BTW, did you notice that the altered regtest you posted still doesn't
work properly?  The final diminuendo spanner is still suicided due to
invalid bounds.

Cheers,
Neil

http://codereview.appspot.com/4630070/