New makefile component_wrapper.mk allows some variables to be set
before component.mk is evaluated. This properly fixes problems with
sdkconfig being hard to access in all phases of the build.
Including component_common.mk is no longer necessary and will print a
deprecation warning for components which use it.
For third party components (lwip and expat), compilation flags are adjusted to silence existing warnings (i have manually checked that all warnings are benign).
In components/esp32, replaced use of WIFI_DEBUG with ESP_LOG functions.
Only remaining warning is in FreeRTOS queue.c, and it may be a useful one.