Make the sidebar dynamic

[nnseva]

Now the sidebar is excellent to apply to the static-functioning map when the sidebar tab list considered to be static, not changeable in runtime.

Sometimes it is necessary to have a tab list dynamic. It is useful for some applications when the tab list should be controlled by later-requested data, plugin list for example.

The code now analises the sidebar definition div at the initialization time. It would be useful to have a separate function to reinitialize sidebar at runtime to adopt a new content inserted there dynamically.