1. suppport mesh type, mesh ID, router and IE crypt func&key at any time after mesh is initalized.
2. support modify parent at any time after mesh is configured.
3. modify manual networking example.
4. update header file.
5. fix issues in root conflicts handling.
6. add max length of beacon to menuconfig.
7. fix issue when received a beacon without DSSS.
1. new APIs: esp_mesh_get_subnet_nodes_num() and esp_mesh_get_subnet_nodes_list().
2. fix hard to find the parent during connect.
3. disable Wi-Fi channel switch function.
4. fix a typo of MESH_EVENT_NO_PARENT_FOUND.
1. add APIs to set/get announce interval values.
2. add API to enable/disable the min rate to 6Mbps for data packages.
3. add APIs to set/get RSSI threshold values.
4. fix ap_loss.
1. add mesh_assoc_t to esp_mesh_internal.h file.
2. rename "node" to "device" in esp_mesh.h.
3. add MESH_EVENT_SCAN_DONE event.
4. add APIs esp_mesh_scan_get_ap_record() and esp_mesh_scan_get_ap_ie_len() to get scan results.
5. modify API esp_mesh_set_self_organized() by adding parameter "select_parent".
6. modify API esp_mesh_set_parent() by adding parameter "parent_mesh_id"
7. add manual networking example.
1. fix issues on sending beacon caused by too much tx retries on other packets.
2. modify not to scan if rc exists when connect.
3. modify scan dwell time to default 120ms fo root.
