New Feature: One time passwords. The user can call the limesurvey login at /limesurvey/admin and pass username and a one time password which was previously written into the users table (column one_time_pw) by an external application. Furthermore there is a setting in config-defaults which has to be turned on (default = off) to enable the usage of one time passwords.

git-svn-id: file:///Users/Shitiz/Downloads/lssvn/source/limesurvey181@6570 b72ed6b6-b9f8-46b5-92b4-906544132732