4.0.0 - Release Candidate 1

This is a pre-release to prepare you for the upcoming 4.0.0 version of Sming Framework.
Below you will find an impressive list of new features, improvements and bug-fixes.

New features

• Initial support for multiple architectures. At the moment ESP8266 and Host with ESP32 coming soon. ( #1675 )
• Modular build system ( #1724 ). Beware of changed behaviour when using environmental variables ( #1758 ).
• Host Emulator (#1692)
• Added support for both ArduinoJson version 6 and 5 ( #1752 ). The default version is now version 6.
• New documentation system based on sphinx ( #1766 ). The new documentation is located at https://sming.readthedocs.io/en/latest/.
• Clock framework and Polled Timers ( #1821 )
• Integrated libsodium v1.0.18 as a component ( #1797)
• Added support for time zones and sunrise/sunset calculation #1840
• File upload support in the HttpServer. #1792
• Added support for BME280 and MCP23008 arduino libraries. #1763
• Initial CAN Bus support. #1646
• Added malloc_count Component to track heap usage #1743
• Enforced C11 standard #1695

Improvements

• WiFi improvements ( #1812, #1802 )
• Unified Callback Timer API ( #1831 )
• Updating internal SDK to NON-OS version 3.0.1. ( #1832 )
• BodyParser improvements: ( #1823, )
• Fixed Esp8266 partitions, added 8Mbyte and 16Mbyte device support #1800
• Decreased latency in MqttClient publishing. Latency is less than 1ms. #1761
• Fixed custom heap #1745

Bug fixes

• Fixed array bounds issue detected via GCC-8 on Host build #1709
• Fixed memory leak in MqttClient #1742
• Fixed UpdServer_Echo. #1775

All PRs that were merged in this release can be seen from here