FUCKING READ THE TEXT OK?????

here's what i did:
1. override setBackground in UserMailEntryComponent to force inner
labels to set their background color too.
2. labels in UserMailEntryComponent set to opaque ( setOpaque(true) ),
otherwise background color wont show.
3. add class UserMailCellRenderer (implements
ListCellRenderer<UserMail>), this class manages how the cells in the
list are rendered.
4. made UserMailCellRenderer make the selected entry in different color

FUCKING READ THIS TOO
try and make each entry have some sort of a border so it could be
distinguished from the entries around it..