Work time recording + bugfixes

Added bwork, ework and wtime commands for work time recording.

Eval, cost and sort command + bugfixes

Added:

• system for time cost estimation
• sort command that enables user to see all todo/in progress tasks in order in the tree

Fixed:

• Push state propagation bug

Changed:

• Fix ancestors state function name changed to propagate state

New command and improved todo command

Added froot command and improved todo command

First release

v0.0.1

Fix problem with up and down arrow keys console hints