Add IPAddress fromString

teensy/IPAddress.cpp

     return 4;
 }
 
+bool IPAddress::fromString(const char *address)
+{
+	uint16_t acc = 0; // Accumulator
+	uint8_t dots = 0;
+
+	while (*address) {
+		char c = *address++;
+		if (c >= '0' && c <= '9') {
+			acc = acc * 10 + (c - '0');
+			if (acc > 255) {
+				// Value out of [0..255] range
+				return false;
+			}
+		} else if (c == '.') {
+			if (dots == 3) {
+				// Too much dots (there must be 3 dots)
+				return false;
+			}
+			_address.bytes[dots++] = acc;
+			acc = 0;
+		} else {
+			// Invalid char
+			return false;
+		}
+	}
+	if (dots != 3) {
+		// Too few dots (there must be 3 dots)
+		return false;
+	}
+	_address.bytes[3] = acc;
+	return true;
+}
+
 #endif

teensy/IPAddress.h

     IPAddress(uint32_t address);
     IPAddress(const uint8_t *address);
 
+    bool fromString(const char *address);
+    bool fromString(const String &address) {
+        return fromString(address.c_str());
+    }
+
     // Overloaded cast operator to allow IPAddress objects to be used where a pointer
     // to a four-byte uint8_t array is expected
     operator uint32_t() { return _address.dword; };

teensy3/IPAddress.cpp

 	}
 }
 
+bool IPAddress::fromString(const char *address)
+{
+	unsigned int acc = 0; // Accumulator
+	unsigned int dots = 0;
+
+	while (*address) {
+		char c = *address++;
+		if (c >= '0' && c <= '9') {
+			acc = acc * 10 + (c - '0');
+			if (acc > 255) {
+				// Value out of [0..255] range
+				return false;
+			}
+		} else if (c == '.') {
+			if (dots == 3) {
+				// Too much dots (there must be 3 dots)
+				return false;
+			}
+			_address.bytes[dots++] = acc;
+			acc = 0;
+		} else {
+			// Invalid char
+			return false;
+		}
+	}
+	if (dots != 3) {
+		// Too few dots (there must be 3 dots)
+		return false;
+	}
+	_address.bytes[3] = acc;
+	return true;
+}
+

teensy3/IPAddress.h

 #define IPAddress_h
 
 #include <Printable.h>
+#include <WString.h>
 
 // A class to make it easier to handle and pass around IP addresses
 
 		_address.bytes[3] = *address++;
 	}
 
+	bool fromString(const char *address);
+	bool fromString(const String &address) {
+		return fromString(address.c_str());
+	}
+
 	// Overloaded cast operator to allow IPAddress objects to be used where a pointer
 	// to a four-byte uint8_t array is expected
 	operator uint32_t () {