869 display ltsversion in web interface footer
If XIVO-VERSION-LTS file is present, the version is constructed as eg. Version: 2017.LTS1 (2017.03).
The version "2017.03" is kept in separate variable to construct XIVO_DOWNLOAD_URL.
Closes #869
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
If XIVO-VERSION-LTS file is present, the version is constructed as eg. Version: 2017.LTS1 (2017.03).
The version "2017.03" is kept in separate variable to construct XIVO_DOWNLOAD_URL.
Closes #869