HeaderFilters (Angular 2)
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Shows how to create custom filter cells in our FlexGrid control.

The sample customizes the column headers by adding an extra row with merged 
cells.

An itemFormatter function is used to customize the content of some column 
header cells with filter editors. The itemFormatter is also used to customize
the display of some columns to show hyperlinks.

This sample is based on a sample provided by 'dhtmlx'. The original sample
is here: http://dhtmlx.com/docs/products/dhtmlxGrid/.

System requirements
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Please refer to the description in the readme.txt file of the Wijmo Explorer for Angular 2 sample.