Show correct filename when reporting errors

[avh4]

Should show the input filename instead of <location> in the following:

Processing file tests/test-files/recursive-directory/nested/invalid.elm
ERRORS
-- SYNTAX PROBLEM --------------------------------------------------- <location>

I ran into something unexpected when parsing your code!

See Main.hs#printError

[Janiczek]

Should the "Processing file xyz.elm" message stay there or will it be rendered obsolete (and should be deleted) with the <location> placeholder properly showing the filepath?

[avh4]

I'm not sure, but hopefully it will be obsolete after replacing <location>

[Janiczek]

One problem I can see (even in your example here) is that the path to the file will be too long for the row with <location>. Should we maybe show just the filename?

[avh4]

We should try to do the same thing elm-make does when you give it a long path.

[Janiczek]

OK so the behavior is overflowing the 80-chars column, not breaking any lines. Also see the ## ERRORS line. We'll have to change that too (right now our version of it doesn't match the style of elm-make

## ERRORS in dlooooouhy-adresar/dalsi-vnoreny/MujProgram.elm ###################

-- TYPE MISMATCH --------------- dlooooouhy-adresar/dalsi-vnoreny/MujProgram.elm

## ERRORS in dlooooouhy-adresar/dalsi-vnoreny/a-jeste-dalsi/can-we-go-deeper/MujProgram.elm 

-- TYPE MISMATCH - dlooooouhy-adresar/dalsi-vnoreny/a-jeste-dalsi/can-we-go-deeper/MujProgram.elm

[avh4]

Fixed in 5756a8d.