CBDATA: log memory leak situations when --enable-debug-cbdata

CBDATA objects are supposed to be explicitly locked and unlocked by all
users. The nominal 'owner' of the data is also supposed to mark it as
invalid when unlocking its reference.

If a CBDATA object reaches 0 locks and is still valid, it therefore
follows that either the locking or invalidate has not been properly
implemented.

Now that we are migrating to CbcPointer usage instead of explicit
lock/unlock macro calls we have started encountering these situations.
Any object reporting a 'leak' must be investigated;
 a) perhapse RefCount is better?
 b) using CbcPointer consistently and invalidating correctly.
Bug 4093: source-maintenance.sh errors and warnings due to wrong tools/options
Windows: link libgcc and libstdc statically

MinGW builds require static linking to libgcc and libstdc++ in order to
run natively on windows without additional DLL installation.
Bug 4024: Bad host/IP ::1 when using IPv4-only environment
Bug 3803: ident leaks memory on failure

Begin the process of conversion for IdentStateData to an AsyncJob.

* convert the object from CBDATA struct to a class with
CBDATA_CLASS2() API.

* Bug 3803 is caused by a lack of proper cleanup and consistent exit
actions terminating the job. Take the core logic changes from the
tested bug patch and;

 1) define a swanSong() method to cleanup the memory allocated

 2) define a deleteThis() method to emulate AsyncJob::deleteThis()

* Locate all code paths leveraging conn->close() to trigger cleanup
via the connection close handler and convert to explicit deleteThis()
with excuse. Including a few which were not but need to in order to
terminate the job correctly as fixed in bug 3803 patch.

The actions performed are nearly identical to the original code. The
differences are that many code paths now omit an AsyncCall step going
via the Comm close handler, and that all paths terminating the IDENT
lookup now go through swanSong() cleanup.


Further cleanup converting to a full AsyncJob is not included, since
there is an explicit hash of running IdentStateData object pointers
being used in the old code.
3.5.0.1
Boilerplate: update release script COPYRIGHT file action