Description of problem:
When changing one's own password, the user should first be prompted to enter his/her current password. 
This will protect the user from having anybody else change it for him/her.

Version-Release number of selected component (if applicable):
ipa-server-2.0.0-23.el6_1.2.x86_64
ipa-client-2.0.0-23.el6_1.2.x86_64

How reproducible:
always

Steps to Reproduce:
1.Login to ipa client machine, as say user1, whose password is say, password1
2.To change password, user1 now runs the command:
ipa passwd

Actual results:
This prompts user1 to enter new password.

Expected results:
Before prompting for new password, it should have prompted user1 to enter current password.
This will ensure that user1 is indeed the person changing his/her own password, and not somebody else.

Additional info:
output from server's /var/log/httpd/error.log:
[Thu Sep 15 10:27:37 2011] [error] ipa: INFO: one@TESTRELM: passwd(u'one', u'********'): DatabaseError
[Thu Sep 15 10:27:45 2011] [error] ipa: INFO: one@TESTRELM: ping(): SUCCESS
[Thu Sep 15 10:27:55 2011] [error] ipa: INFO: one@TESTRELM: passwd(u'one', u'********'): DatabaseError