Make sure infinoted properly depends on infinoted-plugin-manager

It looks like the dependency tracking works when specifying the relative
path in infinoted_0_6_LDADD, but not the absolute path based on
${top_srcdir}. It seems strange to me, but it seems to work.
Allow group and other access to files created in the storage

If this is not wanted, it can be prevented by setting the umask
appropriately.
infinoted: Set umask to system value instead of 0077

This is only relevant when infinoted is started in daemonized mode.
libdaemon resets the umask, but we don't want that, so that the system
administrator can specify the permissions to use for the root directory
with the umask. See #617.