[LPM] ESP8266 and DS1820 DeepSleep (#1591)

Add support for the ESP8266 deep sleep and required change for DS1820 sensor used in my project.

Allow defining DS1820_RESOLUTION and DS1820_INTERVAL_SEC in ENVIRON without editing config file.

Allow DTimeBetweenReadingmq2 Env. MACRO change without editing source config file.

Added some an example ENVIRONMENTS

Add ESP8266_DEEP_SLEEP_IN_US to nodemcuv2-all-test

main/config_MQ2.h

@@ -55,7 +55,9 @@ extern void MQ2toMQTT();
 #  endif
 #endif
 
-#define TimeBetweenReadingmq2 10000
+#ifndef TimeBetweenReadingmq2
+#  define TimeBetweenReadingmq2 10000
+#endif
 /*----------------------------USER PARAMETERS-----------------------------*/
 /*-------------DEFINE YOUR MQTT PARAMETERS BELOW----------------*/
 #define subjectMQ2toMQTT "/GAStoMQTT/mq2"