bob inspect input has undefined behaviour

[zuzuleinen]

For a Bobfile:

build:
  build:
    input: "*"
    cmd: echo "Hello build!"

running bob inspect input build will display the number of inputs, ex. "Task build has 3 inputs"

For

build:
  build:
    cmd: echo "Hello build!"

running bob inspect input build will say "Task build has 0 inputs"

However, it should say "Task build has 3 inputs" because based on our docs "By default the entire directory is considered (*)" for input.

[zuzuleinen]

If task semantics gets merged #276 this bug will be no longer valid, because in that PR input becomes a mandatory node.