Package installer: Information

- 99-cdrom.sh: do nothing if /dev/loop0 is not linked with
  $image_dir/$stagename
- install2-init.c: missing of /altinst is not error
- install2: logging of initinstall and preinstall, error output only
  to log
- install2-action-functions: redirect stdout to stderr when run script
- install2: save logs and screenshots at the end of installation
- 27-metadata-install-scripts.sh: remove output redirection to
  install2.log
- 00-remove-installer-pkgs.sh: enable verbose for rpmi

- 99-cdrom.sh: fixate name altinst for zero image /mnt/altinst

- doc/common.html: fix typo