Add an excel export option to the results of a livetable

It could be interesting to have a livetable option that displays a link that generates an excel file of the livetable results the user can download.
We may think about parameters for this option, such as

• All results
• Limited to xx results (perf issue)
• Only displayed columns
• All properties of the class, etc.

If it's too complicated for all XWiki livetables, it could be at least used in AWM.
Excel export: http://extensions.xwiki.org/xwiki/bin/view/Extension/LiveTableExcelExport+Macro