Add -Dfile to show parsed dag, for debugging, mostly.
fix whitespace
add -Dfile to manpage
Write in dag_file only special and exported variables
fix whitespace
Add support for multiple bindings
spaces for alignment
Treat appending variables as a separate case.

This fixes a bug in which appending to nodes variables would modify dag
variables.
whitespace
Change lookups to multiple bindings
Keep special variables in a set
Change export_list to export_vars set.
Treat resources as just other variables.
Remove category->variables.

They were not useful, and cluttered the code.
Consolidate special vars declarations.
Close over environment for unbinded variables
Move resources from category to nodes
whitespace
Do not wake parents when child is blocked on wait4.

This basically removes this test:

(child->state==PFS_PROCESS_STATE_WAITPID) && (parent->wait_options&WUNTRACED)

which would wake a parent if the child is blocked on wait. The actual test
should look to see if the process has stopped due to a signal. [A process
waiting is not stopped, it is sleeping.]

Parrot should have a separate stop state for processes to fully comply with
wait semantics but this is a larger change as tracking stops with ptrace is
very version dependent. This will be fixed in a future pull request.  For now,
this corrects pfs_process_wait to no longer return results for children that
are blocked on wait.

Fixes #304.
Do not wake parents when child is blocked on wait4.

* parrot-wake-wait:
  Do not wake parents when child is blocked on wait4.