Stable vendor/repair, custom task queuing, custom selling options

Vendor/repair using waypoints should now be fairly stable...the bot uses a custom task with 10001 priority which will get popped as soon as the idle loop comes up. I've also added custom task queuing...see the changes in wt_core_taskmanager for examples. In the "supply run" function for the toolbox you can see an example of queuing two tasks at the same time...the second task takes another cycle of the task/idle loop to activate but does work. I've added custom selling options which allow users to specify what types of items they want to sell beyond weapons, armor, and junk, so that should make people who want to vendor more happy (along with being able to use waypoints to vendor). I tested it fairly extensively using a single bot and also spent some time with multibots but you should probably run some tests with group botting just to be safe. I'll be on tomorrow if you find any major bugs.