Make `DefaultsError` a real `Error` object
v2.4.4
Add --noerr to turn off argument name checking

for now only used for keys passed to `-c` or `-b`.
v2.4.5
v2.4.6, because npm is foobar
Properly scope `catch` identifier when --screw-ie8

Fix #344
AST_Catch shouldn't really inherit from AST_Scope.  Fix #363

I hereby acknowledge that figure_out_scope has become a mess.
v2.4.7
minor
Add `drop_console` option to the compressor
Merge pull request #245 from ForbesLindesay/patch-1

Make `DefaultsError` a real `Error` object
semicolons
bugfix #242
Merge pull request #371 from colorhook/master

bugfix #242
minor