Info: make builddir add owner write permissions to all files

Last minute pull request for 1.3.2!

Since bcfg2-info isn't normally run as root, it can remove write
permissions from itself in certain situations.  This patch ensures
that owner write is added to the mode for all files written by
builddir.

For example, suppose a bundle specifies a file /etc/foo/private
with mode 0444.  The POSIX tool will create /etc/foo with mode
0555.  Any subsequent files that are specified to exist in
/etc/foo will not be created because bcfg2-info will hit a
permission denied error.