Local database API functions are not available to BlueGigaClient #24

It can be useful to access the local device attributes of a BLE112 device used as a client, such as the firmware_revision (0x2a26) or the device name

Unfortunately, the following methods are only available to BlueGigaServer:

• read_by_handle
• read_type
• ble_rsp_attributes_read
• ble_rsp_attributes_read_type
• (and maybe their write-access counterparts)

It does not seem it would hurt to move these implementation into the parent class (BlueGigaModule) so that both the server and the client may access these methods.