* Also enhanced reporting error exit reporting through the scons logger to provide
the exception in the compilation report.
* More error exits in scons should do this.
* Hard imports now have a registry and can be expanded by plugins with
additions at compile time.
* Dedicated helper for fixed imports to use less C code for
standard imports.
* Dedicated node for fixed imports added, for use in standalone
mode in the future.
* Dedicated node for builtin imports, so their special handling is not
in the generic import builtin node anymore.
* Plugins now can look ahead to a module such that they can prepare
by e.g. adding hard imports dynamically created for lazy loader
".pyi" files before loading the code.
* The plugin method for modifying the source now gets the filename,
so it doesn't have to reconstruct it, for our new case where we
want to read nearby ".pyi" file.
Kay Hayen
John Vandenberg