Eliminate BindingsDerivedSources.txt

The dynamically generated BindingsDerivedSources.txt is now redundant,
as it is exactly the same list as the static list main_interface_idl_files

This simplifies compute_dependencies.py considerably.

Also:
* Move action_derivedsourcesallinone.py from build/scripts to bindings/scripts, as it's only used here.

I think I may be able to eliminate the separate support_* lists in a
followup, as they were separated exactly to avoid being included in
BindingsDerivedSources.txt.

R=haraken

Review URL: https://codereview.chromium.org/135903003

git-svn-id: svn://svn.chromium.org/blink/trunk@165303 bbb929c8-8fbe-4397-9dbb-9b2b20218538