Minor modifications after meeting.

The modifications done were:
	- ExperimentListModel has an example of how to avoid reloading the
complete list of conditions when a condition is removed. This example
should be extented to ConditionListModel and SampleListModel.
	- experimentData.zul components were ordered.
	- home.zul and index.zul windows were positioned at the center of the
page using a width of 960px.
Aligned / centered views.
Fixed "Cancel" button when filling new experiment in experimentData.zul.
Added delete experiment button. Added navigation button to Experiment
Data.
Added experimentDesign.zul view.
Added "color" field to ConditionGroup, Replicate, and Sample entities.
Colors are now correctly saved.
Added header, footer, and (non-working) spreadsheet.
Fixed alignment for header and footer. Fixed spreadsheet view.
Confirmation pop-up to delete experiment.
Changes done after demonstration.

ZK spreadsheet dependency added to pom.xml.

Experiment views (data and design) merged into one single page
(experiment.zul).

Minor improvements in the experimentDesign.zul to allow replicate and
sample selection.

Other minor GUI changes.
Implemented filter bar to search experiment by name in home.zul. Fixed
alignment to header in experiment.zul.
Now Conditions, Samples, and replicates can be removed from the
experiment via a button in experimentData.zul.
Added checkbox behaviour to Conditions in experimentDesign.zul
Implemented methods to know whether an Entity is on a plate or not.
Changed entity.isOnPlate to entity.isOnPlate()
Implemented method to generate row / column titles. Currently causes
NullPointerException.
Fixed bug on method inflate: char z was 'a' or 'A' instead of 'z' or
'Z'.
PlateEditor created.

PlateEditor created as an extension of Spreadsheet component. The
purpose of PlateEditor is to have a custom component for the replicate
placement in plates.
Fixed uppercase option for cell title.
Added an OnCellClick method to PlateEditorComposer for painting the
plate.
Changed Replicate's attribute plate to plateId.
Added a way to know if an experiment is on a plate.