The commit occurred in 4.5 branch xen2server
Within CloudStack we have used the term "Xen" to refer to both Citrix XenServer and Xen Cloud Platform (XCP) based hypervisors. While both of these options use the same integration point, XenAPI (XAPI), neither are actually Xen. In order to support a pure Xen based hypervisor (or more precisely a Xen Project based one), we first need to reconcile the use of Xen and XenServer within CloudStack. This feature document covers the first phase of that; removal of "Xen" as a concept replacing it with XenServer. Replacement with XenServer is the preferred option since in June of 2013, packaged XCP was officially made end of life in favor of XenServer. While other "XenServer" implementations have appeared, most notably xenserver-core, they retain the same XenServer/XAPI interface and can be treated as compatible.
Xen: A bare metal hypervisor now known as the Xen Project hypervisor and is Linux Foundation collaborative project. The current release is 4.4, and is actively developed.
XenServer: A packaged virtualization product from Citrix containing the Xen Project Hypervisor. The current release is 6.2 SP1, and is actively developed.
Xen Cloud Platform: A semi-packaged open source implementation of Citrix XenServer. Also known as XCP. The latest release is 1.6 and development has stopped.
XAPI: The Xen Management API and toolstack used in XCP and XenServer. XAPI is a Linux Foundation collaborative project, and is still under development.
With the exception of configuration variable names, hypervisor name values, and descriptive elements, users should be unaware of these changes.
XEN_NETWORK_LABEL changed to XENSERVER_NETWORK_LABEL in ApiConstants
Changes do not introduce new libraries or security modules.