CHANGE: Report errors from server

There was no catching of errors from the server, for example in case the input path is not existing.
And clear the list

To avoid confusion, as there was an error, it's best to clear the list of items.
In case of all errors, still clear the table

if there is an exception, I was not clearing the table
Better catching/reporting of the errors

The errors from the submit methods need also better catching.
clear the table only at the end of the on() call

no need for code duplication
FIX: the reader is JSON, so there must be a jsonData
FIX: the new limit was not taken into account

The store was no updating the number of events to display.
Merge pull request #153 from sposs/patch-5

CHANGE: Report errors from server