1. If the root is specified (FIXED-ROOT) by set type or set parent, change ie.mesh_type to MESH_ROOT before connect to router.
2. Release esp_mesh_recv_toDS when the root becomes non-root.
3. esp_mesh_set_type now supports MESH_IDLE and MESH_STA.
4. Fix ie.rc_rssi is not updated during scan and vote.
5. Fix ie.mesh_type do not match ie.layer caused by parent switch.
6. Fix during root switch, the original root doesn't disconnect from the router after it receives the switch request from the new voted root. (root switch happens by invoking esp_mesh_waive_root).
7. Fix the routing announce timer is not stopped immediately in a new root if the new root is transformed from non-root.
8. Choose the candidate with less ie.assoc when doing parent switch.
esp_err_t provided by esp_err.h and thus is required and not optional.
While the python script adds the header, it wraps it with an __has_include
directive that is not supported on all compilers (notably GCC 4.8).
Closes https://github.com/espressif/esp-idf/pull/3424
