Synced with Circle Step 48

• Synced with Circle Step 48.
• Update Mbed TLS to release v2.28.9.
• Fixed invalid payload in MQTT client.
• Fixed broken GitHub action caused by missing dependencies of the old QEMU 6.0.0 release.

Full Changelog: v16.5...v16.6

Synced with Circle Step 47

• Synced with Circle Step 47.
• Update Mbed TLS to release v2.28.8.
• Aligned toolchain version with Circle (ARM Gnu toolchain 13.2.Rel1).

Fixed issue #35

• Fixed issue #35 "No output from printf() in samples/02-stdio-hello with v16.3".

Full Changelog: v16.3...v16.4

Synced with Circle Step 46

• Synced with Circle Step 46.
• Fixed duplicate definition of fcntl().

Synced with Circle Step 45.3.1

• Synced with Circle Step 45.3.1.
• Update Mbed TLS to release v2.28.4.

Synced With Circle Step 45.2

• Synced with Circle Step 45.2.
• Update mbed TLS to release v2.28.3.
• Aligned toolchain version with Circle (ARM Gnu toolchain 12.2.Rel1).

Circle Step 45.1, new functions

• Synced with Circle Step 45.1.
• Implemented functions that previously returned an error code:
  • getcwd() and chdir()
  • dup(), dup2() and fcntl(... F_DUPFD ...) (Note: Only the F_DUPFD command is implemented for fcntl()!)
  • stat() and fstat()
  • fsync()
  • ftruncate()
  • isatty()

Synced With Circle Step 45

• Synced with Circle Step 45.
• Updated mbed TLS to release v2.28.1.
• Updated GitHub action to fix deprecation warnings.

Synced with Circle Step 44.5

• Synced with Circle Step 44.5.

Synced with Circle Step 44.4.1

• Synced with Circle Step 44.4.1.
• Updated mbed TLS to release v2.16.12.
• New configure command line option --option for specifying additional preprocessor defines
  consistently across all libraries.

This release replaces the faulty withdrawn release v15.11.