Support filenames with spaces

[bmwiedemann]

seen in the wild in the ghostscript-fonts-grops package
(when comparing i586 and x86_64 results)

• Includes some test coverage
• Needs more testing.
• Needs more double-quoted $file

[olafhering]

Why does filling $files work they way it was done in that patch? I would expect "foo bar" to expand to two strings. $files should probably become an array.

[bmwiedemann]

files is really one long string including spaces and newlines at that point and filesarray is created from it later.
You can play with

x=`echo -e foo bar\\\\nbaz`
grep x "$x"
grep x $x