Added arduino libs

libraries/EnableInterrupt/utility/ei_ExternalTiny24.h

@@ -0,0 +1,24 @@
+// Support for the 14-pin ATtiny24/24A/44/44A/84/84A
+#if ! defined(EI_NOTINT0)
+#ifdef EI_SECTION_ENABLEEXTERNAL
+// NO switch (arduinoPin) { // ONLY 1 External Interrupt pin.
+#ifndef EI_NOTINT0
+    GIMSK &= ~_BV(6); // Disable interrupts since we are (possibly) changing interrupt settings
+#ifndef NEEDFORSPEED
+    externalFunctionPointer = userFunction;
+#endif
+    MCUCR &= (~_BV(0) & ~_BV(1)); // reset the flags prior to
+    MCUCR |= mode;                // set them the way we want
+    GIFR |= _BV(6);
+    GIMSK |= _BV(6);
+#endif
+#endif // EI_SECTION_ENABLEEXTERNAL
+
+#ifdef EI_SECTION_DISABLEEXTERNAL
+#ifndef EI_NOTINT0
+  GIMSK &= ~_BV(6);
+  MCUCR &= (~_BV(0) & ~_BV(1)); // reset the flags
+  GIFR  |= _BV(6); // using a clue from the ATmega2560 datasheet.
+#endif
+#endif // EI_SECTION_DISABLEEXTERNAL
+#endif // ! defined(EI_NOTINT0) && ! defined (EI_NOTINT1) && ! defined (EI_NOTINT2)