ToDo: ----------------------------------------------------------------------
* performance is horrible
implement partial save and render
autosave when add column and row
* implement context menu functions
** implement creation of tables
** implement save and refresh data (implement positive lock, with last update)
** implement alert remote modification -> create status
-> NOT SAVED
-> SYNCRONIZE
-> DESYNCRONIZE
* implement data delivery
* replace jquery for native js
* do cross-browser testing
* be happy hacking
* apply styles
* implement memento
* change textareas for input text
DONE:
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* onmouse over column name appears two buttons + and - for adding column or removing -> override by contextual menu
* add a last column with + and - for adding/removing row
* create table as object, table id as reference
** implement reordering of rows
* implement copy and paste cell