Revert "create_virtualimage: extend script with:"

This reverts commit 467914e8fde4828f5bee79c13f2fff4fa1e8da00.

needs rework:
 - $4 (system part size?) should be optional
 - /dev/loopXpX don't work on many distros. 'losetup -o' should be used
Revert "    update create_virtualimage script"

This reverts commit 34854f95b60ffc10d240e5b57ef73b39a6eca2bf.

needs rework:
 - /dev/loopXpX don't work on many distros. 'losetup -o' should be used