readd lost promo dvd plugin
Make sure correct grub2 module path is used for ec2hvm firmware

Currently the grub2 module path is set correctly with firmware
set to 'ec2' but not if set to 'ec2hvm'
Fixed typo: boottimout -> boottimeout
Merge pull request #411 from coolo/master

Added promo dvd plugin for openSUSE 13.2
Make sure to wait for the storage device if set in root=
- v7.01.10 released
Fixed grub2 xen module list

Some modules available in grub2 are not available for grub2
in xen, e.g chain
- v7.01.11 released
Don't skip grub2 prefix setup for ec2|ec2hvm
- v7.01.12 released