Updated thunderbird package fixes security vulnerabilities

Several flaws were found in the processing of malformed content. Malicious content could cause Thunderbird to crash or, potentially, execute arbitrary code with the privileges of the user running Thunderbird (CVE-2013-5590, CVE-2013-5597, CVE-2013-5599, CVE-2013-5600, CVE-2013-5601, CVE-2013-5602). It was found that the Thunderbird JavaScript engine incorrectly allocated memory for certain functions. An attacker could combine this flaw with other vulnerabilities to execute arbitrary code with the privileges of the user running Thunderbird (CVE-2013-5595). A flaw was found in the way Thunderbird handled certain Extensible Stylesheet Language Transformations (XSLT) files. An attacker could combine this flaw with other vulnerabilities to execute arbitrary code with the privileges of the user running Thunderbird (CVE-2013-5604). Also, the thunderbird-lightning extension has been updated to a version that is compatible with the updated Thunderbird.