Two fix about preview in the panel for unique lines :
- The fallback preview was not refreshed anymore It was caused by a
  change in the way we use CanvasSE, we must now force the regeneration
  of the inner BufferedImage
- The previews in the table were too huge. They are smaller now so that
  we can see more lines at once.
Adds a warning dialog warning that a classif is huge.
The threshold is currently set to 100. Cancelling with this window acts
as cancelling the progress monitor. Clicking OK lets the computation
continue. The calculation is still cancellable through the
progress monitor.
Removes the UOM management from configuration editors.
I still must add UOM management in unique values.
First version with UOM management for recoded lines.
Still have some refreshment problems...
Fix the displaying of proportional values.
It has been broken, don't know when... It was a typing problem I fix
here by changing the SQL used to build the sample DataSource.
Adds UOM management in unique values.
It refreshes the previews of the table and of the fallback.
Should solve the problem described in #300
Adds some javadoc
Improvements asked in #299 and #301
Labels displayed for unique values are better and the name associated to
the new symbolizers is set according to the legend's type.
That's what we can call a useless variable...
Merge pull request #307 from agueganno/polishing/recode-for-lines

Some polishing in the simple legend editor