Initial s390-tools-2.0.0 import

This commit is based on the s390-tools-1.39.0 version.

Changes on top of s390-tools-1.39.0:

 - Add MIT license to all source files
 - Add LICENSE file
 - Transform REAMDE to README.md (markdown)
 - Add AUTHORS.md file
 - Add CONTRIBUTING.md file
 - Move changelog from README to CHANGELOG.md file

Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>

iucvterm/doc/ts-shell/authorization-sample.conf

@@ -0,0 +1,24 @@
+# Terminal server authorization configuration
+#
+# See ts-shell(1) manual page for file format.
+
+
+## Examples -- System lists
+
+# alice is authorized to connect to guest1 .. guest5
+alice = list:guest1,guest2,guest3,guest4,guest5
+
+## bob is authorized to connect to systems listed in the file "test-systems.list"
+bob = file:/etc/iucvterm/systems/test-systems.list
+
+# authorize all members of the Linux 'admins' group to connect to systems
+# listed in the file "admin-systems.list"
+@admins = file:/etc/iucvterm/groups/admin-systems.list
+
+
+## Examples -- Regular expressions
+
+# eve has authorization to connect to systems with
+#   a) names starting with 'guest', followed by exactly 2 digits
+#   b) names starting with 'lnx', followed by 5 alphanumeric characters
+eve = regex:(?:guest\d{2}|lnx\w{5})