support all the different data types

[brettlangdon]

right now it barely supports any because I just want to get a working prototype done.

but should support xml and uri and date and time and etc etc.

[brettlangdon]

wg_int wg_encode_null(void* db, wg_int data);
wg_int wg_encode_int(void* db, wg_int data);
wg_int wg_encode_char(void* db, char data);
wg_int wg_encode_record(void* db, void* data);
wg_int wg_encode_double(void* db, double data);
wg_int wg_encode_fixpoint(void* db, double data);
wg_int wg_encode_date(void* db, int data);
wg_int wg_encode_time(void* db, int data);
wg_int wg_encode_str(void* db, char* str, char* lang);
wg_int wg_encode_xmlliteral(void* db, char* str, char* xsdtype);
wg_int wg_encode_uri(void* db, char* str, char* nspace);
wg_int wg_encode_blob(void* db, char* str, char* type, wg_int len);
wg_int wg_encode_var(void* db, wg_int data);