Add space between strings to be concatenated

Without those spaces, the output would be:

  ... figletdoesn't...
  ... espeakdoesn't...
fix tool-installed?

Previously it always returned a truthy value (a procedure). Now
it properly returns a boolean.

It has been internally restructured to search for the given filename
in PATH, since the `-v' trick is not valid anymore (espeak's `-v'
requires an argument).