* fbt: added separate script for Windows env setup; moved flash targets from firmware.scons to SConstruct; added Blackmagic support with automatic probe port resolution; added apps.c rebuild on any manifest.fam changes; fixed simultaneous flash & debug ops
* fbt: added networked BlackmagicResolver mode; added `get_blackmagic` target for IDE integration
* fbt: cleanup
* fbt: docs update; fixed blackmagic lookup on certain usb hubs
* fbt: removed explicit python serial port import
* fbt: cleanup
* fbt: raising exception on multiple serial blackmagic probes
* fbt: added --git-tasks; fixed typos
* fbt: fixed --extra-int-apps handling; scripts: moved storage.py & selfupdate.py to App() framework
* fbt: changed pseudo-builders to PhonyTargets with commands; added link to latest build dir as build/latest
* fbt: Restored old ep git handling
* fbt: dropped git tasks & dirlink.py
* fbt: removed extra quoting in fbt.cmd
* docs: added flash_usb to ReadMe.md
Co-authored-by: あく <alleteam@gmail.com>
