[feature] Add framework versioning

[az0uz]

This is a feature request to add framework versioning.
In the platform.ini file, it is already possible to specify the version number via semver (related #410 #413) but only for the platform and libraries, not for the framework version.

I'll explain why I need it:
I am using an atmega 32u4 with the arduino framework, and I need to use the watchdog witch is not yet supported on this board but the work is in progress as seen in:

• [AVR] Fix problems with USB CDC auto-reset arduino/Arduino#6055
• https://github.com/arduino/Arduino/issues/6033
• Add infinite loop after wdt_enable call arduino/Arduino#6064

to be able to still use the watchdog without waiting for this feature to be implemented, I am patching the arduino framework by:

1. using a project specific home_dir to not mess with the other project
2. using an extra_script with a env.AddPreAction("$BUILD_DIR/FrameworkArduino/", apply_watchdog_mod) to check/apply the watchdog patch
3. testing in my function apply_watchdog_mod if the patch was applied and if not apply it.

This works great but I wouldn't be confident using that in production without being able to depend on a specific arduino framework version. If I try to install my code a new system, and the framework is updated with a new version of the files I am patching, the patch will fail.
So I would like to be able to depend on a specific framework version and upgrade everything myself when the feature is implemented in the official version of the framework.

[ivankravets]

framework is updated with a new version of the files I am patching, the patch will fail.

Framework is a part of a development platform. You can fork existing development platform and replace Arduino part with yours. See

• http://docs.platformio.org/en/latest/platforms/creating_platform.html#manifest-file-platform-json

[ivankravets]

Please reopen if you still have any questions