[FEAT] Ext.data.Model: optimize `id`

for memory savings and faster processing

Signed-off-by: Oleg Verych <olecom@gmail.com>
[FAST] Ext.data.Model->set: death-to-hasownproperty

http://phrogz.net/death-to-hasownproperty
Object.defineProperty(Object.prototype,'toSourceCode',{
   enumerable:false,  // this is the default value, but let's be very clear
   value:function(…){
   ...
   }
});

Signed-off-by: Oleg Verych <olecom@gmail.com>
[FAST] Ext.data.Model->set: one check for `modifiedFieldNames`

Signed-off-by: Oleg Verych <olecom@gmail.com>
[FAST] Ext.data.Store.{totalCount,snapshot}: no V8 hidden class change

Signed-off-by: Oleg Verych <olecom@gmail.com>
[FAST] Ext.data.Store.loadData: is inefficient method warning

Signed-off-by: Oleg Verych <olecom@gmail.com>
[FAST] Ext.data.Store->loadRecords: optimize

* open code `addAll()` which uses `arguments`
* shuffle assignments

Signed-off-by: Oleg Verych <olecom@gmail.com>
[FAST] Ext.StoreManager->lookup: optimize for the most likely code path

Signed-off-by: Oleg Verych <olecom@gmail.com>