fixed initializer and Wformat warnings
Merge pull request #1094 from BytesGalore/fix_print_format_warnings_test_vtimer

test:test_vtimer fixed initializer and Wformat warnings
make: print error if make was executed in the root

Fixes #1104, alternative to #1178.
Merge pull request #1183 from Kijewski/issue-1104

make: print error if make was executed in the root
sys/crypto/twofish/twofish.c: removed unused variables
sys/crypto/twofish.c: removed trailing whitespace
sys/crypto/twofish/twofish.c: added macros and restored variables

Removed macros from ``sys/include/crypto/twofish.h``