Updated mxml packages fix security vulnerabilities

Updated mxml packages fix security vulnerabilities: An issue has been found in Mini-XML (aka mxml) 2.12. It is a stack-based buffer overflow in mxml_write_node in mxml-file.c via vectors involving a double-precision floating point number and the ‘’ substring, as demonstrated by testmxml (CVE-2018-20004). An issue has been found in Mini-XML (aka mxml) 2.12. It is a use-after-free in mxmlWalkNext in mxml-search.c, as demonstrated by mxmldoc (CVE-2018-20005). In Mini-XML (aka mxml) v2.12, there is a use-after-free in the mxmlAdd function of the mxml-node.c file. Remote attackers could leverage this vulnerability to cause a denial-of-service via a crafted xml file, as demonstrated by mxmldoc (CVE-2018-20592). In Mini-XML (aka mxml) v2.12, there is stack-based buffer overflow in the scan_file function in mxmldoc.c (CVE-2018-20593).