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>

libccw/Makefile

@@ -0,0 +1,14 @@
+include ../common.mak
+
+lib = libccw.a
+
+all: $(lib)
+
+objects = ccw.o
+
+$(lib): $(objects)
+
+install: all
+
+clean:
+	rm -f *.o $(lib)

libccw/ccw.c

@@ -0,0 +1,42 @@
+/**
+ * ccw - Channel Command Word function library
+ *
+ * Process ccw_devid
+ *
+ * Copyright 2017 IBM Corp.
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "lib/ccw.h"
+
+/**
+ * Parse a string into a ccw_devid structure
+ *
+ * @param[in,out] devid   Pointer to ccw_devid structure to be initialized
+ * @parm[in]      id      String to parse
+ *
+ * @returns       true if the input string has been parsed successfully;
+ *                otherwise false.
+ */
+bool ccw_parse_str(struct ccw_devid *devid, const char *id)
+{
+	unsigned int cssid, ssid, devno;
+	char d;
+
+	if (strncasecmp(id, "0x", 2) == 0)
+		return false;
+	if (sscanf(id, "%4x %c", &devno, &d) == 1) {
+		cssid = 0;
+		ssid = 0;
+	} else if (sscanf(id, "%2x.%1x.%4x %c", &cssid, &ssid, &devno,
+		   &d) != 3) {
+		return false;
+	}
+	ccw_devid_init(devid, cssid, ssid, devno);
+	return true;
+}