Proposal for common 802.15.4 radio driver API definition.
shell: strings in shell_command_t are const
shell: Comment internal members, too

Closes #979.
Merge pull request #1065 from Kijewski/issue-979-2

shell: Comment internal members, too
Merge pull request #925 from rousselk/radio-driver-api-proposal

Proposal for common 802.15.4 radio driver API definition.
tests: added missing chronos to blacklist
Merge pull request #1063 from Kijewski/shell_command_t-fix-const

shell: strings in shell_command_t are const
Merge pull request #1066 from mehlis/test-bloom-bytes-followup

tests: added missing chronos to blacklist
test: thread: blacklist boards
Merge pull request #1062 from mehlis/test-thread-blacklist

test: thread: blacklist boards