Bugfix: Fake build settings specification inconsistently defines path_sources_object...

Bugfix: Fake build settings specification inconsistently defines path_sources_object and fix consistency problem.

The "path_sources_object" setting designates that this can handle multiple files but the implementation fails to handle this.
Rewrite the implementation to handle multiple object files by creating each object file separately.

The specification also designates that the "build_name" is used, which makes no sense for multiple object files.
Remove this such that the object files are created based on the original source file name (without the extension).

Clarify the documentation, updating the specification.

Break out the individual settings that are related that should be updated for consistency.
These are path_sources_headers, path_sources_library, path_sources_program, and path_sources_script.