1. Add process of prepare write request packets
2. Add process of execute write request packets
3. Add process of reliable write request packets
4. Fix bug of processing read blob request packets
5. Fix bug of processing write request packets
6. Optimize error check and process in stack
1. change all gatt cb function to 3 args and function type. add gattc_if/gatts_if as second argument
2. delete gatt_if of "gatt cb param"
3. separate conn_id and gatt_if from conn_id
4. change the demo code as the gatt changed
1. Actually, btc & api are the same module thing. So the type defined in api header file can be included by btc c/h files.
Besides, why btc & api should be separated, because that user may be aware of api and api refer defines/types, rather than other non-refer things.
All defines/types that user won't use should be put in btc directory (and define with prefix "btc_"), and which will be used by user should be defined with prefix "esp_" .
2. rename attribute value(all is value, not data)
1. which named uuid is esp_bt_uuid_t type
2. which named id is xxx_id_t type, such as service_id_t char_id_t, include inst & uuid
3. share include directory
