Add project based west.yml

[jalinei]

• Modules version stored in state.json now correctly compared with west.yml revision hash
• Add the possibility to provide dependencies through a project based west.yml file.
• Add the possibility to skip large installation times due to default west.yml

Fixes #22
Tested on Ubuntu 20.04, I don't have access to a Windows machine to check classic curses..

Questions from my side :

• I guess I should add the same workaround in clear_deprecated_package than in clean_up to wipe .git folder on windows machines ? I can add that commit when confirmed.
• Is it really necessary to have install-deps.py script called from tool manager ? With the current logic, there is no way to skip the initial download, that encompass all packages defined in framework based west.yml which leads to unnecessary disk space occupation & installation times.
  (Example in Ststm32 platform : https://github.com/platformio/platform-ststm32/blob/develop/platform.py#L124)

My proposal would be to launch install-deps.py only from platformio-build.py, this way a potential local west.yml can be detected and install time can be dramatically reduced (from 3GB+ to approx 600MB in our case).

Opinion :

• I don't really understand the added value of --secondary-installation parameter. I got that it permits to distinguish if script is launched from tool-manager or by platformio-build.py but in practice it does not change much.

[jalinei]

@valeros did you have time to get an eye on this one ? 😃

[valeros]

Hi @jalinei, sorry for the delay, I'll look into the PR soon. In the meantime, could you please put together a few projects to properly test out this new functionality? I'm especially interested in more advanced examples that involve project-specific west.yml that partially overrides the default one.

[jalinei]

My test branch is that one : https://github.com/jalinei/Core/tree/test_west

• it can't compile without downloading dependencies from thingset that are not present in regular west.yml.
• it has a specific version of zcbor that differs from regular west.yml (to test that after a default install, version is now correctly compared using state.json (can also be tested by forcing another hash version in state.json)
• it has a forked hal to showcase how much we could shrunk the dependencies (only shipping stm32g4xx) for our specific case. Not working yet, because install-deps is still launched from project agnostic main platform.py so non expert user will still download default modules