* pmsleep refactor
* Shortened swtmr disabled message
* Added swtimer debug module option to user_modules.h.
* Added comments to user_config.h.
* Fixed error in documentation for node.sleep()
* remove blank sntp.c that got added in during rebase onto dev(6218b92)
* Added #ifdefs around SWTIMER_REG_CB to prevent inclusion of disabled
code
Added `node.egc.meminfo()` to expose LVM usage (to make the regular
`node.egc.ON_MEM_LIMIT` option usable).
Extended the `node.egc.ON_MEM_LIMIT` option to also take negative limits,
in which case that's taken as a request to keep a certain amount of heap
available for non-Lua use.
* mbedtls 2.7.0 (mbedtls-2.7.0-0-g32605dc8)
Wholesale import, with a few changes from earlier preserved through.
Ideally we would soon get to the point of having no divergences from
upstream.
* tls: add function to adjust mbedTLS debug level
* Fix some subtle timing issues with gpio.pulse
* Add the pulse:update method
* Allow getstate to work on stopped pulsers
* Make gpio.mode(, gpio.OUTPUT) actually set the output mode
* Added some more documentation
in float build, uV and sign are included in mV
in int build, uV and mV are absolute, sign is -1, 0, 1
added rounding of uV values
added optional test function
* ads1015 is supported, up to 4 devices can be connected at the same time
* removed debug, updated documentation
* changed to oop API
* added __gc to handle active timer cleanup
* reworked argument validation and error reporting
* stack is no longer messed up after __del
* ws2812 effects and color utils modules added
* Added documentation for new modules to mkdocs.yml
* changed mode option to string, documentation, default modules fixed
* updated user_modules.h