Previously device tests included information such as access point SSID/password at compile time. This made it difficult to compile test binaries once and then send them to multiple test runners for execution.
This change adds a command to the test library to set environment variable on the target device: “setenv key value”. C library setenv/getenv facility is used to store variables.
Test runner, tests, and makefile are updated to use this functionality.
* device test for #4516 (WiFiClient leaking)
* simply count the number of connections that do not change heap
* remove unused heapLost
* + python server (to not depend on gateway's opened tcp port)
* remove old&bad define
* fix another old address
