Ability to block user accounts until they have validated their email address

i won't implement this change for the following reasons:

1. using the access permissions of the pre-auth user, you can already greatly control the access a user has to the site. considering that LT leverages access control to do it's job, i'd rather see a permissions-based solution, like an 'access own user profile' setting. however, i feel that setting is out of scope for the module. it could easily be accomplished in a mini-module, though
2. i think it's bad workflow to not allow a user to access their own account while in the pre-auth role. for instance, they need access to their account in the event that they need to have another validation email sent to them
3. doing it as an LT setting overly complicates LT's workflow for little gain

so i'd suggest you look at the mini-module option in #1 if you really want this.