Determine which methods should be required by the ILayout interface

We need to eliminate our reliance on casts to BaseLayout and AbstractLayout
in the core in favor of casts to ILayout. To make this a reality we need to
evaluate which methods need to be included in the interface and which
should be removed.

Methods to be removed:
- bounds

Methods that need further discussion:
- dataField
- labelField
- referenceRepeater
- currentReference
- currentValue
- currentLabel
- dataTipLabelFunction
- dataTipPositionFunction

We should consider splitting the debated method over other interfaces which
better encapsulate the intention of those methods.

Original issue reported on code.google.com by mvand...@gmail.com on 4 Jun 2009 at 2:10

gvhung / axiis

Determine which methods should be required by the ILayout interface #11