Doc: Avoid newlines in references
This seems to work, but makes it very hard to process references with automated scripts.
The changes were mostly created with the following command:
find Documentation/ -name "*.itely" -o -name "*.itexi" | \
xargs perl -0777 -pi -e 's/ +(\(?\@p?x?ref{[^},]*)\n([^},]*})(\)?[,.]?) *\n?/\n\1 \2\3\n/g'
and one manual fixup in Documentation/en/notation/input.itely
.