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
Merge pull request #1033 from Kijewski/buildsizes

make: comprehensive list of the boards' filesizes
make: remove clutter

Remove some outdated example code, and simplify output folder creation.
make: parallelize creation of board and base code
 make: add `BOARD_INSUFFICIENT_RAM` blacklisting

Currently most blacklistings for examples and tests are done because the
board provides too little RAM or ROM. Besides of the actual linking all
the compiling should nevertheless work just fine.

This PR adds the variable `BOARD_INSUFFICIENT_RAM` to tell the
`buildtest` to compile the code for a board, but omit the linking step.
Use `BOARD_INSUFFICIENT_RAM` in examples and tests