Add license info to subunit2html
Add license info to subunit2html

Subunit2html is being split out into another repo. To keep track of
copyright and license info update it with an appropriate apache header
(for the edits made on top of the original source whose license is
preserved as is).

Change-Id: I6fc16d316012fd3e1c196f74df25d725a310f6dc

noorul/os-project-config,dongwenjuan/project-config,noorul/os-project-config,Tesora/tesora-project-config,citrix-openstack/project-config,dongwenjuan/project-config,anbangr/osci-project-config,anbangr/osci-project-config,openstack-infra/project-config,coolsvap/project-config,coolsvap/project-config,openstack-infra/project-config,citrix-openstack/project-config,Tesora/tesora-project-config