FW-725. only remove packet not handled by IEEE802154E component.

Merge pull request openwsn-berkeley#449 from openwsn-berkeley/develop…

…_FW-782

FW-782. Update msf implementation

Merge pull request openwsn-berkeley#359 from openwsn-berkeley/develop…

…_FW-540

FW-540. XON/XOFF-based openserial.

Release as 1.18.0 version.

Merge pull request openwsn-berkeley#442 from openwsn-berkeley/develop…

…_FW-777

FW-777. create selftest project to test whether the mote on OpenTestbed is able to run sub-GHz apps.

Merge pull request openwsn-berkeley#438 from openwsn-berkeley/develop…

…_FW-773

FW-773.openmote-b- port (CC2538 2.4GHz radio only)

Merge pull request openwsn-berkeley#426 from openwsn-berkeley/develop…

…_FW-741

FW-741. Disable MSF add/delete cells after first cell is added.

Merge pull request openwsn-berkeley#395 from openwsn-berkeley/develop…

…_FW-548

FW-548. implementing MSF algorithm for adapting to traffic.

FW-602. return SUCCESS code even no cells are available to add or be …

…candidate for relocation.

Merge pull request openwsn-berkeley#267 from openwsn-berkeley/develop…

…_FW-492

FW-492. SF0 implementation.