Update ofxOSC to support double.

I needed double support to send gps coordinates over OSC.

But this brings up a potentially larger issue -- why are we only supporting a limited subset of the tag types:

```
enum TypeTagValues {
    TRUE_TYPE_TAG = 'T',
    FALSE_TYPE_TAG = 'F',
    NIL_TYPE_TAG = 'N',
    INFINITUM_TYPE_TAG = 'I',
    INT32_TYPE_TAG = 'i',
    FLOAT_TYPE_TAG = 'f',
    CHAR_TYPE_TAG = 'c',
    RGBA_COLOR_TYPE_TAG = 'r',
    MIDI_MESSAGE_TYPE_TAG = 'm',
    INT64_TYPE_TAG = 'h',
    TIME_TAG_TYPE_TAG = 't',
    DOUBLE_TYPE_TAG = 'd',
    STRING_TYPE_TAG = 's',
    SYMBOL_TYPE_TAG = 'S',
    BLOB_TYPE_TAG = 'b',
    ARRAY_BEGIN_TYPE_TAG = '[',
    ARRAY_END_TYPE_TAG = ']'
};
```

Our support (including the double I am adding):

```
typedef enum _ofxOscArgType
{
	OFXOSC_TYPE_NONE,
	OFXOSC_TYPE_INT32,
	OFXOSC_TYPE_INT64,
    OFXOSC_TYPE_FLOAT,
    OFXOSC_TYPE_DOUBLE,
	OFXOSC_TYPE_STRING,
	OFXOSC_TYPE_BLOB,
	OFXOSC_TYPE_BUNDLE,
	OFXOSC_TYPE_INDEXOUTOFBOUNDS
} ofxOscArgType;
```