added script that executes cbmc
replace NULL with 0
added ELEKTRA_ASSERT
fix #124

allow Elektra to be installed as user (non-system install)
fix gcc warnings
fix conflicts test

+ make sure that error message is also specified (will be easier to fix
  the testcase next time)
fix python3+lua bindings

were broken because _kdb.so was overwritten (3x in same folder)
also make CMakefiles more consistent between swig bindings