Add test suite for KDB principal flags

Test kadmin.local reading of principal flag specifiers, kdc.conf
setting of default_principal_flags, and kadm5.acl restrictions.  Only
really tests one flag at a time.

Also start requiring Python 2.5 for the test suite.  It's been around
for long enough, and some syntax features such as conditional
expressions are useful.

https://github.com/krb5/krb5/commit/ea62dd834f343b2dddea81c8295f2f8876c83090
Author: Tom Yu <tlyu@mit.edu>
Commit: ea62dd834f343b2dddea81c8295f2f8876c83090
Branch: master
 src/configure.in          |    3 +-
 src/tests/Makefile.in     |    1 +
 src/tests/t_princflags.py |  126 +++++++++++++++++++++
 src/util/k5test.py        |    2 +-
 src/util/princflags.py    |  264 +++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 394 insertions(+), 2 deletions(-)