htdocs can contain user data

Reason : might be dangerous.

Use two dollars to pass to instance recipe.

Conflicts:
	software/kvm/software.cfg

Use new recipes in KVM to make instance not raise when no frontend is found,
Don't request slave kvm frontend instance on SAME machine,
Check if frontend is available using a promise

Use new recipes in KVM to make instance not raise when no frontend is found,
Don't request slave kvm frontend instance on SAME machine,
Check if frontend is available using a promise

This reverts commit 35c5c950.