Handle failure states / errors gracefully

[jaythejones]

zack:house_with_garden: 1:01 PM
2 notes about the Task Manager…i think we should pass back all failure states in executeTasks in the result and every where we call executeTasks we at the very least log the error. Also, in store TaskStore we should log anything that might be hinting towards corrupt data in the store…like in store(), remove(), loadIndex() etc…