spawn: function auto-loading other functions are not included in spawned code

[icasimpan]

Example:

projects/hello/lib/greet.bash.inc

greet() {
   autoload_functions "banner"
}

Will include the `banner()" function within spawned code but not the caller, that is, greet is left out which is obviously wrong.
Investigate and put a fix as this is a common scenario.