sct-1: Task images can appear in random or sequential order (depending on type created)

[naknomum]

• task.randomized boolean added to model
• Pulldown for random vs sequential added to task creation screen
• Column for ordering added to task list screen
• Filter by ordering (any, random, sequential) added to task list screen
• Annotating flow follows random or sequential according to task setting
• Ground-truthing flow follows random or sequential according to task setting