* added defmacro!
* revert #924#924 had an error and should never have been merged in the first place. (see #903)
* put back import getargspec
Without the `formatargspec` this time.
* Give better error message on failed macro expansion
Better error messages work most of the time. In cases where there are
parameters that aren't valid in Python, error message shown is rather
ugly. But this is better than no error messages at all and such
macros with strange parameter names are rather rare.
* fix flake8 errors
* Minor English improvements
e588b4928d