2.3.2 - Extract (unzip) action, duplicated configs, new server-side errors model

• implement "extract" action to unzip archives #22;
• removed duplicated configuration options (common for both client and server sides) #109;
• new isolated way to handle server-side errors;
• bugfix: wrong scroll behavior in IE #151;
• bugfix: error when copying to a folder with spaces #153;
• bugfix: not loading userfiles folder when it's empty #154;

Backward incompatible changes:

• server-side language files specific for a particular connector should be removed;
• new format for server-side errors: label + arguments to be treated with JSON lang files;
• security.allowFolderDownload server-side configuration option moved to options section;
• removed the following server-side configuration options (see details in #109):
  • overrideClientConfig (since no duplicated options now);
  • options.culture (since no translations at the server side now);
  • security.allowChangeExtensions (no affect security, clint-side only now);
  • upload.paramName (no sense to change value for this option);
  • upload.chunkSize (client-side solely option);
• reduced a list of parameters in "initiate" server-side action;