Fixed A/D hotkeys with regard to browser's Alt+D
Added endless scroll (closed #5)

The code for paged collections now feels like playing ping-pong with
callbacks, and like I have no idea on who should render who.

It works, though.
Changed file dropper to autodetect "allowmultiple"
Removed unnecessary values
Worked on post uploads (#11) - added GUI
Shifted data transform responsibility from service
Introduced entity property getters/setters
Turned on notifications about unused variables
Fixed unused variable in abstract search service
Fixed magic strings in Dao layer
Switched to sqlite (closed #38)
Fixed vendor autoloader placement
Changed EntityConverter inner workings

In order to understand data types returned by DB engine better,
EntityConverter was changed to use getter/settter methods instead of raw
properties. That way, the methods inside entities can cast to desired
data types when accessed.
Fixed account activation for first user

Until now, AuthService used to check for empty e-mail in order to tell
whether an account is activated. This was wrong for following scenario:

1. User doesn't enter any e-mail.
2. Because he is about to become the first user to register, he will
   become an administrator.
3. Administrators don't need to confirm their e-mail address. Activation
   e-mail is not sent, code for e-mail activation is run instead.
4. The user succeeds to create an e-mail-less administrator account.
5. The user fails to login due to unconfirmed e-mail.
6. The code that activates an e-mail just moves unconfirmed e-mail to
   primary e-mail. That was the bug, there's no e-mail to confirm.

Things got (hopefully) simpler now, since I added separate column for
indicating whether account is activated.
Fixed extra spaces between items in top navigation
Added additional type safety