Alpha-level support for Keil RTX on mbed OS

This release brings the support of Keil RTX with uVisor on mbed OS, plus several other improvements.

New features

• Integration in Keil RTX in mbed OS.
• Secure dynamic allocation APIs.
• Box initialization routines.
• Register gateway.
• vMPU recovery generalized for both Kinetis and ARMv7-M MPUs.
• APIs for per-box interrupts disablement and re-enablement.

Work in progress

• Remote Procedure Call (RPC). New API signatures have been published. The alpha-level implementation will follow soon.

Deprecated features

• Secure gateway. Cross-box communication will be implemented with RPC gateways.

Bugfixes

• Several ARMv7-M-specific bug fixes.
• Fixed a bug that sent the device into lock-up after a hard fault.
• Fixed checks on revision numbers for Cortex-M devices.

Miscellaneous improvements

• Optimized memory protection for ARMv7-M devices with shared SRAM.
• Build artifacts are grouped into the target/build option/configuration-specific folder.
• Documents have been grouped into API vs. core documents.
• Improved style and consistency.