boards: fixup for pyterm renaming
Merge pull request #1543 from LudwigOrtmann/pyterm-fixup

boards: fixup for pyterm renaming
doc: fix spelling in core/include
Merge pull request #1545 from LudwigOrtmann/spellingbee

doc: fix spelling in core/include
make: added targets 'debug-server' and 'reset'
[SQUASH ME] added vars and buildtests for targets

- added DEBUGSERVER and RESET vars to Makefile.vars
- added output of those to Makefile.buildtests
boards/stm32fXdiscovery: added debug-server target

added "make debug-server" target for
- stm32f0discovery
- stm32f3discovery
- stm32f4discovery