unittests: support Makefile.include in test suites

This change will pull in the `Makefile.include` for every test suite
that is compiled in.

Fixes #1205.
make: fix clean together with TLSF
Merge pull request #1230 from Kijewski/fix-clean

make: fix clean together with TLSF
Initial import of the x86 port

Currently this works only in qemu.
Merge pull request #764 from Kijewski/implement-x86

Initial x86 port: "qemu-i386"
s/PROJECT/APPLICATION/g

fixes #548
Merge pull request #1224 from thomaseichinger/pro-to-app

make: s/PROJECT/APPLICATION/g
Documentation: Create README.md for the CCN-lite client and relay
Merge pull request #1227 from emmanuelsearch/CCN-documentation

CCN documentation
Merge pull request #1207 from Kijewski/unittests-makefile.include

unittests: support Makefile.include in test suites
Fix trailing whitespaces

Fixes #1138
Merge pull request #1163 from authmillenon/fix-whitespaces

Fix trailing whitespaces
Add a missing constant in 'radio_tx_status_t' enum
Merge pull request #1239 from rousselk/radio-API-again

Add a missing constant in 'radio_tx_status_t' enum
cleanup licenses to fix #392