Remove string attribute from views

issue2350

view/forecast_complete_ask_form.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
-<form string="Choose dates">
+<form>
     <label name="from_date"/>
     <field name="from_date"/>
     <label name="to_date"/>

view/forecast_complete_choose_form.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0"?>
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
-<form string="Choose products" col="1" >
+<form col="1" >
     <field name="products"/>
 </form>

view/forecast_form.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
-<form string="Forecast" col="4">
+<form col="4">
     <label name="warehouse"/>
     <field name="warehouse"/>
     <label name="destination"/>

view/forecast_line_form.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
-<form string="Forecast Line" col="4">
+<form col="4">
     <label name="forecast"/>
     <field name="forecast"/>
     <newline/>

view/forecast_line_tree.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
-<tree string="Forecast Lines" editable="bottom">
+<tree editable="bottom">
     <field name="product"/>
     <field name="quantity"/>
     <field name="minimal_quantity"/>

view/forecast_tree.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
-<tree string="Forecasts">
+<tree>
     <field name="warehouse"/>
     <field name="state"/>
     <field name="from_date"/>