riched20: EM_GETLINE implementation and test

[Mike McCormack]

James Hawkins wrote:

> To be as portable as possible, we code to the lowest common
> denominator.  Not all compilers support L"".  We adhere to C89, but I
> can't remember what it says about L"", if anything.  The point is that
> WCHAR blah[] ={...} will work for every compiler.

wchar_t is an int on some versions of gcc. It can be made a short using 
-fshort-wchar, but only later versions of gcc (3.0+) support that flag.

Mike