Most notably, utils_get_line_endings() and document_open_file_list()
don't support -1 as the size anymore.  If the size should be computed
from null-terminated data, the caller code must take care of doing so.

git-svn-id: https://geany.svn.sourceforge.net/svnroot/geany/trunk@5855 ea778897-0a13-0410-b9d1-a72fbfd435f5