Add support for row template in Nebula Grid

Render "rowTemplate" property in GridLCA#renderInitialization.

Change-Id: Id132ae217b58b517a33615e3fa9de8189b4eba00
Signed-off-by: Ivan Furnadjiev <ivan@eclipsesource.com>
Don't set text/selection on disposed Text/Combo/CCombo

Text and selection of Text/Combo/CCombo (with verify listener attached)
are not applied directly when processing the incoming message in the
coresponding operation handler. Setting text and selection is wrapped in
ProcessActionRunner to ensure correct event handling. When parent Shell
is closed in the same request where text/selection is set, "widget is
disposed" exception is thrown. In this case shell is closed first (all
child widgets are disposed) and then text/selection are set on already
disposed widget.

Add dispose check in Text/Combo/CComboOperationHandlers before setting
text and selection.

449350: Press keys then escape key fast enough in dialog generates
"Widget is disposed" exceptions
https://bugs.eclipse.org/bugs/show_bug.cgi?id=449350

Change-Id: I1075e6f2740fd4001eec17c8b9d3ba02d0508a82
Signed-off-by: Ivan Furnadjiev <ivan@eclipsesource.com>
Don't send "modify" notify operation on disposed Text/Combo

Client-side Text/Combo widgets schedule a delayed (500ms) request when
"modify" notify operation need to be sent. It's possible to dispose the
widget (from the server-side) in this interval. In this case
Text/Combo._onSend function fail with JS error (remote object is not
registered as Text/Combo is already disposed).

449350: Press keys then escape key fast enough in dialog generates
"Widget is disposed" exceptions
https://bugs.eclipse.org/bugs/show_bug.cgi?id=449350

Change-Id: I65c3b8071db9882cf3a7ab9289e19dbc1b204e48
Signed-off-by: Ivan Furnadjiev <ivan@eclipsesource.com>
Fix invalid value of Grid selection event index property

If Grid selection event index property is unknown, it should not be
included in the notify operation. In Grid.js#_fireSelectionChanged there
is a check if index is number, but this check does not work for null
values - isNaN( null ) returns false.

Use typeof instead of isNaN to make Grid.js#_fireSelectionChanged work
with null index value.

449432: Nebula grid: UnsupportedOperationException after click on RWT
hyperlink
https://bugs.eclipse.org/bugs/show_bug.cgi?id=449432

Change-Id: I393a71e15b55091241c4d4027e921795e7e464d7
Signed-off-by: Ivan Furnadjiev <ivan@eclipsesource.com>