Duplicated icon _id on SelectIitem + icons in ListGrid

[borutr]

Example:
Add an icon to Continent field in listType example at http://www.smartclient.com/index.jsp#listType:

isc.ListGrid.create({
    ID: "countryList",
    width:500, height:224, alternateRecordStyles:true, 
    canEdit:true, editEvent:"click", modalEditing:true,
    data: countryData,
    fields:[
        {name:"countryCode", title:"Flag", width:50, type:"image", imageURLPrefix:"flags/16/", imageURLSuffix:".png", canEdit:false},
        {name:"countryName", title:"Country"},
        {name:"continent", title:"Continent",
            valueMap:["Europe", "Asia", "North America", "Australia/Oceania", "South America", "Africa"],
            icons: [ {} ]
        }
    ]
})

Steps to reproduce the problem:
- run the example
- click on the Country column in the first row (United States) in order to edit the row
- click the picker icon on Continent column (North America): it works OK - the item list shows / hides properly
- click on the Country column in the second row (China) in order to edit the row
- click the picker icon on Continent column (Asia): it DOESN'T WORK: the item list is not shown because the [...] icon gets the click instead of picker icon

Rationale:
The problem is that the picker icon and the [...] icon has the same _id value: "_0" in the second and following edits.

It seems that when editing second row the icons property is reused from the first row, so icons _ids are already assigned, while the _nextIconId is reset to 0. The picker icon gets _id "_0" by calling _setIconId(), which is the same as the [...] icon _id. When the clicked icon is serched, the [...] is find before the picker icon, so it gets the click.

Workaround:
Set icon _id to an user defined value. Icon _id is mangled to $151 in SmartClient 70rc2:

...
        {name:"continent", title:"Continent",
            valueMap:["Europe", "Asia", "North America", "Australia/Oceania", "South America", "Africa"],
            icons: [ {$151: "_my_id"} ]
        }
...