run-tests: fix whitespace nonsense

merge with mpm

run-tests: on windows, put correct python at front of PATH The older approach of trying to copy the python executable into the test directory was doomed to fail. There remains one weakness with this approach: if you've run "make local", tests may pick up the wrong extension DLLs from inside the source tree. I don't know why this happens. A reasonable workaround for now is to test either using --local or with a working directory that does not contain built DLLs.

run-tests: fix exename on Windows

run-tests: support running tests in parallel on windows Previously, we used os.spawnvp, which doesn't exist on Windows, and isn't needed anyway (the command line begins with an absolute path). We also need a slightly more convoluted way to wait for processes without specifying an order on Windows, as it lacks os.wait.

makefile: allow local builds to work on windows/mingw32

check-code: make 'missing whitespace in assignment' more aggressive New warnings: > a.b=ab missing whitespace in assignment (the pattern did not accept '.' on the left hand side) > a=a missing whitespace in assignment (the right hand side pattern never matched a single character) > a=a + 7 missing whitespace in assignment (the pattern only matched one character after the identifier following =)

check-code: there must also be whitespace between ')' and operator The check pattern only checked for whitespace between keyword and operator. Now it also warns: > x = f(),7 missing whitespace after , > x = f()+7 missing whitespace in expression