Backport change from trunk:
queryparser/lemon.c: Sync change from upstream: "In Lemon, when
comparing the output to the *.h file to see if it has changed, make
sure that the proposed new output and the preexisting output are the
same size before deciding that they are the same".  Generated code
is identical, but this will fix misbehaviour in a build from a
non-clean tree if new tokens get appended to queryparser_token.h.

git-svn-id: file:///home/xapian-svn/xapian/branches/1.2@18363 6b2f1b92-a4f3-0310-943f-de3cbe41748b