Makes several broad changes:
- removes dead code that dealt with the online build system
- replaces export function with a much simpler one that:
- does not copy any sources
- the zip file hits the disk
- the mbed_config.h hits the disk
- the project files hit the disk
- nothing else hits the disk
- exporters use Resource object scanned with a toolchain
- progen exporters don't optionally build a project instead they have a
build function that may be called afterwards
- much of the code passes pylint (have a score of 9 or above):
- project.py
- project_api.py
- export/__init__.py
- export/exporters.py
- test/export/build_test.py
if we work with relative sources, the flag should be set to True, otherwise
False.
This fixes wrong paths when exporting with --source argument. The exporter would
assume sources were copied, and thus reference them all within the root of the generated
project.