The class was for long no more in use, but the file was left undeleted.

A bit less stuff in the main JsDuck namespace.

Included a mini-library 'regexp-quote' which provides just one but
useful function.

Esprima now rejects those pieces of code as invalid JavaScript.

The new esprima no more considers newlines as part of line comments.

Let Esprima have its window object - otherwise it'll just crash.

We could simply query the forum database every time we need the e-mail
address, but I think it's better to keep interaction with forum database
to a minimum.  Besides, changing the e-mail address happens very rarely
and at least we now have this case covered.

This way we can take advantage of automatic updating of the created_at
fields and don't need to insert new Date() into all of those columns.

The old comments backend worked just fine with one shared connection, so
we shouldn't get quickly into troubles with this approach.

Previously the number of open connections just kept growing and growing
because they never got closed.  At least this problem is now gone -
there's just one open connection which we never close.

- Actaul application files go to comments/lib/
- Jasmine tests go to comments/spec/

The e-mail sender we use is configurable in ./config.js.

- Validator class now takes care of all the validations.
- Request class implements the actual requests performed.
- TableFactory sets up all database connections and provides access to
  Table classes.

Performs queries to:

- retrieve all targets a user has subscribed to.
- retrieve all users who have subscribed to a target.

Added Comments#showVoteDirBy method to set the user who's vote
directions are shown when using the #get #find and #findRecent.

To be able to query the deleted comments, the Comments#showDeleted
method can be called to define whether deleted comments should be
included to the query.  This is implemented through having two
views in the database: full_comments and full_visible_comments.