(Mingle#1849 Gurpreet): Added proper error messages for password confirmation and blank userid

Have added proper error messages for:

1) On create user, if the passwords don't match.
2) On reset password, if the user id is blank.

Added rspec for both, although I was unable to inspect the error message in case of reset password in the rspec test.

I have also added the KEYs in English, Arabic and Chinese files. I skilled french and russian files since they were anyways fully commented out.