Log Message:
Changes 3.1.5.1:
* SourceFormat Enforcement
* Replace most USE_IPV6 with run-time support probing
* Translations: sync with 3.HEAD language updates
* Split-Stack enable DNS and http(s)_port sockets.
* Bug: --with-valgrind-debug failures ignored
* Fixed comm.cc:377: "fd_table[fd].halfClosedReader != NULL" assertion
* Kludge: try to detect system acinclude path, to fix libtool brokenness.
* Bug: search scope for digest_ldap_auth didn't work
* Update libtool autoconf macros to libtool2 style
* Correction documentation of QoS disable-preserve-miss
* Remove .so from SASL build checks
* Bug: AIX support: c only c++ style comments test case
* Bug: AIX support: check libm for log()
* Do not stop accepting just because we got COMM_NOMESSAGE.
* Bug: AIX support: uchar is already define (more)
* Bug: AIX support: uchar is already define
* Bug: crash handling NULL write callback
* Correct Joomla DB auth handling
* Fixed memory leak related to retried requests.
* Prevent memory leaks when cloning Range requests.
* Fixed memory leaks related to Range requests.

Changes 3.1.5:
* Bug: Fix context leak in HttpStateData::processReplyHeader
* Bug: raw-IPv6 address URL with append_domain broken
* Bug: does not send indirect X-Client-Ip in ICAP respmod
* Fix free memory corruption and off-by-on error when comparing SNMP OIDs
* Restart DNS retransmission count when restarting the query as an A lookup
* Bug: HTTP responses with no Date, L-M or Expires can now be cached
* Maintenance: Formater skip libltdl dirs
* SourceFormat Enforcement
* Bug: Fails to detect chunked encoding if not given in all lower case
* Port from 2.7: max_filedescriptor config option
* persistent_connection_after_error is meant to be on by default
* kFreeBSD does not have linux headers. Wrap properly.
* Maintenance: Use system MD5 instead of hard-coded python paths
* Bug: ICAP tokens not logged when using multiple access
* SourceFormat Enforcement
* OpenBSD: Fix build mem.cc warning: converting of negative value