Fix whitespace bugs in PARSE-INTEGER
Fix whitespace bugs in PARSE-INTEGER

Test:
(parse-integer "FontBBox -113 -250 749 801 " :start 8 :junk-allowed t)
Should produce (values -113 13)

Trailing whitespace is treated as junk when :junk-allowed is true,
and does not change the second return value.

froggey/Mezzano,rvedam/Mezzano,rvedam/Mezzano,froggey/Mezzano