[RFC] Fix problems related to Mingw/DJGPP file names containing colons

[DJ Delorie]

>   But there might be some 'exotic' file systems that allow
> both double-quotes and colons as valid characters in their
> filenames.

Any unix-like OS supports that:

$ touch 'foo"bar:grill'
-rw-r--r-- 1 dj games       0 Aug 13 16:46 foo"bar:grill

The only two characters you *can't* put in a file name or subdirectory
name are the NUL character and possibly '/' (I've seen ways to make
filenames with / in them).  Every other character is 100% legal.

>   I am wondering how spaces within filenames are handled 
> inside GDB on mingw32...
>   I just tested... No very well :(

Any unix-like OS also supports spaces in filenames!

$ touch 'foo bar'
-rw-r--r-- 1 dj games       0 Aug 13 16:47 foo bar

These are not new problems, nor are they dos/windows specific.