[libfko] allow MS compatible usernames

Allow usernames that are compatible with Microsoft guidelines as defined
here:

http://technet.microsoft.com/en-us/library/bb726984.aspx

This allows for greater compatibility between fwknop clients on Windows
(for example that may be deployed with Cygwin) and fwknopd on other
systems.  This change was suggested by Gerry Reno, and tracked by Github
issue #114.
[test suite] allow fuzzing_spa_packet file comments to skip particular packets
[perl FKO module] comment out username fuzzing packets that are now acceptable to libfko
[test suite] Added Rijndael+HMAC command execution test
[test suite] Added Rijndael+HMAC NAT rand port via client rc file test
[test suite] added Rijndael+HMAC SPOOF_SRC fwknoprc file test
fix header non-ascii chars, and introduce test suite support for detecting this in source files
Merge branch 'master' of ssh://github.com/mrash/fwknop
[libfko] start on refactoring fko_decode_spa_data() to put SPA field parsing into dedicated functions
[libfko] call SPA field parsers via function pointers in fko_decode_spa_data()
Merge branch 'master' of https://github.com/mrash/fwknop
Merge branch 'ms_compatible_usernames'

This merges in work on #114 to allow MS compatible usernames, and should
help Cygwin (and Windows) users.
ChangeLog updates for 2.6.1
[libfko] add digest verification and length fcns to decode routine
replace malloc() with calloc() calls
[libfko] dedicated parsing functions for decoding client timeout and server auth SPA fields
[test suite] minor bug fix to add udpraw mode for spoofed src test
[libfko] minor error constant label typo fix
[libfko] per-SPA message type field count validation

This commit implements more rigorous SPA packet field count validation
that takes into account expected field counts for each SPA message type.
Two new libfko error codes have been added in support of this, and the
corresponding changes made in the perl and python modules.
[test suite] add lcov html results for gcov profile coverage in --enable-profile-coverage mode