2.1.0 - Selectable and Multiple actions

• implemented selectable view items (mouse dragging & Ctrl key), see manager.selection config options #15, #38;
• implemented multiple actions for selected items (move, delete, download) #11, #15, #38;
• special drag helper while dragging multiple items:
  • shows number items items;
  • prevents on moving (to) protect folder or to the one of selected items;
• provided an ability to open files/folders with mouse dblClick, see manager.dblClickOpen config option;
• improved injection of dynamic assets (js & css) with toast plugin;
• added "afterSelectItem" callback function #73;
• created file to initiate RFM plugin and configure with callbacks and baseUrl #73;
• "select" action now available without window.opener to use RFM inside custom modal windows (bootstrap, jquery dialog, etc.);
• bugfix: scrollbar not showing on initial load #77;
• PHP connector: bugfix comma in filename problem #78;
• composer is added to the project #71;

Backward incompatible changes:

• JSON configuration file "filemanager.config.default.json" has been moved from "/scripts" to "/config" folder;
• have to copy and rename "/config/filemanager.init.js.example" file, along with JSON configuration file;