tonality

A SEGV which occurred if clicking was done very
quickly in file browser was fixed. A problem where
typing very quickly could result in some
keypresses not being registered was fixed.
Thumbnail logic was changed to not store scaled
images if they are below the minimum icon size.

No functional changes were made. This is a port of
version 1.1 from Qt 3.x to Qt 4.x.

A slider for adjusting the overal exposure of the
image was added. Minor bugfixes were made.