native/make: set all binutils with ?= instead of =
native: update support for FreeBSD

works with FreeBSD 10.0 amd64/i386

fixes: #505
native: add tapsetup-freebsd.sh
make: comprehensive list of the boards' filesizes
make: add maketarget to to show the biggest obj files
make: show diffence in buildsizes for two folders
Proposal for common 802.15.4 radio driver API definition.
test_nativenet is only useful for native ...
ccnl: don't include transceiver and defaulttransceiver

This removes the duplicate include of the transceiver.
The transceiver module is a dependency of the
defaulttransceiver, so an explicite include is not needed
core: improved doxygen documentation
Merge pull request #976 from mehlis/doxygen-one-way-malloc

core: oneway_malloc: improved doxygen documentation
Merge pull request #1053 from mehlis/ccnl-make-defaulttransceiver

ccnl: don't include transceiver and defaulttransceiver
test: posix: blacklist boards
Merge pull request #1060 from mehlis/test-posix-blacklist

test: posix: blacklist boards
test: bloom: backlist platforms
Merge pull request #1052 from Kijewski/test_nativenet-only-native

test_nativenet is only useful for native ...
Merge pull request #1022 from LudwigOrtmann/issue_505

native: update support for FreeBSD
Merge pull request #1059 from mehlis/test-bloom-blacklist

test: bloom: backlist platforms
shell: strings in shell_command_t are const
Add basic travis-ci integration

This PR adds the basic integration for [Travis CI][tci].

The config file `.travis.yml` tells the server to setup the basic build
system, and run `compile_test.py`. If not all  examples and tests could be
built, then the Travis CI integration adds a warning to "merge" button on
the bottom of the Github page.

Of course this integration makes little sense until #1049 is resolved,
because new bugs and old bugs cannot be told apart. Also (of course)
only because everything still builds, a PR still can intruduce a
multitude of runtime errors.

This integrations is meant to work additionally to our Jenkings. Users
can activate the test in their own RIOT forks to run the test before
opening a PR to master.

  [tci]: https://travis-ci.org/