#JC-1591: Fixed review remarks, added plugin reloading:
*Now checkbox available if activation error occurs
*Activation message placed at the center of pop-up
*Now activation data passes to controller in request body instead of query
*Added method reloadPlugins which wraps getPlugins
*Plugins reloads now immediately after activation
 *Removed unused code which updates activation of list of plugins
 *Pop-up showing time increased from one second to two seconds