postcss-cli do not copy folder structure from input files when pattern is used #78

Reopened from postcss/postcss#958

I am trying to compile multiple *.pcss files and have the *.css output sit in the same directory. For example, I have the following structure:

src
-- test1
---- 1.pcss
-- test2
---- 2.pcss
-- test3
---- 3.pcss

When running:

postcss --use precss src/**/*.pcss --dir out/

I expect:

src
-- test1
---- 1.pcss
-- test2
---- 2.pcss
-- test3
---- 3.pcss
out
-- test1
---- 1.css
-- test2
---- 2.css
-- test3
---- 3.css

But what I got is:

src
-- test1
---- 1.pcss
-- test2
---- 2.pcss
-- test3
---- 3.pcss
out
-- 1.pcss
-- 2.pcss
-- 3.pcss

So there are 2 issues here:

1. The output doesn't have the same folder structure as the input when used with pattern.
2. I don't seem to be able to specify the output file extension when using --dir.

Any suggestion please?

By the way, it would be great if such options are also available in a config file as that's where I actually configure the options :)