There are two passwords prompts when installing a new site. One for the database, one for the admin user.

For the database: created variable "reenter_db_pass" in class "site", and added prompt input "Re=enter Database Password" to the screen; for the admin user: "reenter_admin_password", and "Re-enter Password".

Generally, created function "compare_var" in class "GtkUI" to check if the password matches its reentry; added the return value of the function to the variable "page[validators]".

In installation, the "next" button is disabled until the password matches its reentry.

Successfully tested on my ubuntu(virtual box)