Log Message:
Update xenkernel415, xentools415 and xenstoretools to Xen 4.15.5
Chnages since 4.15.4:
- includes patches for Xen Security Advisory up to XSA-436 (inclued)
- update seabios to 1.16.0
- better support on some hardware

Complete changes here:
https://xenproject.org/downloads/xen-project-archives/xen-project-4-15-series/xen-project-4-15-5/