IPv6 Support

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The notes below describe what was done in getting pam_radius_auth.so to the point of supporting IPv6.
In addition to adding IPv6 support, a TRACE facility was added, hardtab/whitespace was cleaned up, and
some bug fixes were made.

Following is a rough breakdown of the changes:
-   Began with 1.3.17 from tar.gz, which did not include a few changes in the github repo.
    o   Those changes were applied at the end of the project (see below).
-   Removed hard tab characters using vim's :se ts=8 and :se ts=4 and :1,.retab in sections
    o   Did not realign all text to use same indent rules.  Just removed hard tabs.
-   Code changes to reach a first snapshot of IPv6 support:
    o   Can now handle radius server names that resolve to IPv6 (or IPv4)
    o   Can still of course handle IPv4 addresses
    o   Does not yet handle IPv6 addresses completely due to bracket parsing work to be completed
    o   Replaced IPv4-only gethostbyname calls with getaddrinfo calls
    o   Switched from sockaddr/sockaddr_in IPv4-only to generic sockaddr_storage which handles IPv4/IPv6
    o   Set IPV6_V6ONLY to off, allowing one IPv6 socket to handle IPv6 and IPv4 communication.
    o   Commented out no-longer needed IPv4-only validation code (comments in source for this change).
    o   Added TRACEPRINT to aid with development, debugging, and learning how pam_radius_auth works.
-   Near final snapshot:
    o   Implemented bracket handling etc. to support [<ipv6-address>]:port form where :port is still optional.
    o   IPv6 address can be abbreviated forms, such as  [fdca:1:2:3::4]:1812
    o   Improved debug output around port lookup to prevent some failures on odd input in server config file
    o   Modify Makefile to build normal shared library and a trace version using -DTRACEON
    o   Add comments in less obvious parts of code especially where I made changes.
-   Merged in changes from latest github master version of this project, current as of 5/19/2013.
-   Trace version of library:
    o   Modified the Makefile to build a second library, pam_radius_auth_trace.so with tracing enabled.
        * The trace version can be renamed at runtime to give more debug/trace output if needed.
-   Testing:
    o   Tested with names, IPv6 addresses, and IPv4 addresses against freeradius 2.2
    o   Tested with names, IPv6 addresses, and IPv4 addresses against Windows 2008 NPS
    o   Tested with names and IPv4 addresses against freeradius 2.1 and Windows 2003 IAS
        * freeradius 2.1 and Windows 2003 IAS do not support IPv6.
-   Contact info:  alan.d.carwile@gmail.com      AC Network Software
                   alan.carwile@hds.com          Hitachi Data Systems
-   Credit also to Kentaro Aoki, whose code changes were referenced and helpful along the way.
    o   http://code.google.com/p/pam-radius-ipv6/