Inline additional twi_** helper functions

Sketch uses 270799 bytes (25%) of program storage space. Maximum is 1044464 bytes.
Global variables use 27944 bytes (34%) of dynamic memory, leaving 53976 bytes for local variables. Maximum is 81920 bytes.

401000cc l     F .text1	00000014 twi_delay
401000f4  w    F .text1	0000003b twi_releaseBus
4010015c g     F .text1	00000246 twi_onTwipEvent
401003bc l     F .text1	000001e7 onSdaChange
401005b0 l     F .text1	000002f9 onSclChange
401008ac l     F .text1	0000003b onTimer

0x000000004010741c                _text_end = ABSOLUTE (.)

Author: earlephilhower

cores/esp8266/core_esp8266_si2c.cpp

@@ -364,7 +364,7 @@ inline void ICACHE_RAM_ATTR twi_reply(uint8_t ack)
   }
 }
 
-void ICACHE_RAM_ATTR twi_stop(void)
+inline void ICACHE_RAM_ATTR twi_stop(void)
 {
 	// send stop condition
 	//TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTO);
@@ -376,7 +376,7 @@ void ICACHE_RAM_ATTR twi_stop(void)
 	twi_state = TWI_READY;
 }
 
-void ICACHE_RAM_ATTR twi_releaseBus(void)
+inline void ICACHE_RAM_ATTR twi_releaseBus(void)
 {
 	// release bus
 	//TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT);