- chain debugSend_P into basic _debugSend instead of duplicating code, pass va_list between them
- check if new[] call was successful
- when possible, use stack buffer and fallback to heap buffer only when it is more that 64 chars

* debug: heap fragmentation stat

* Rework method detection

- return check integral type as a result of detection instead of method type
- type-tagging instead of enable_if

* fix alias

* typo

* only need one bool_type instance

* Move heap debug into HeapStats header

- don't show fragmentation stats on the first call
- prettify fragmentation display
- pack function params into helper struct
- naming

* pass external flag instead

* add missing prototypes

- wrapper NTPClient class to avoid inadvertently calling NTP::getTime() while
setting things up
- only call NTP::getTime() when in loop(), install async TimeLib
sync provider and manually set TimeLib time
- randomize sync and delay times

This reverts commit 1471a632bb.