fixed some inconsistencies

Fixed the menu category selection for the server.
Added a "all" option to the category menu.
Verified if the galley has any works to show.
Verified if a member has any works on the members details page.
Verified if the files for the slideshow in the home page are image
files.
Verified if there is any members to show on the members page.
Corrected some errors on the language files.