1628 – Ddoc produces invalid documentation for --- blocks

Adding newlines between ---s produce odd output. Here's a minimal example:
<code>
/**----
----*/class C{}
</code>
produces
<output>
mymodule
 $(DDOC_MODULE_MEMBERS 
class F; 
 $(DDOC_DECL_DD
</output>
Removing the line feeds between ---'s or filling the empty line with content hides the errors.

Created attachment 589 [details] 
Patch against DMD2.042 svn 416
Also fixes bug 122.

This is pretty simple, we just need to cope with the case where the code section is empty. 
I also generate an error for cases like:
/**
 this code doesn't have a proper ending
---
 int x;
*/
which I think is better than generating an invalid html file.

changeset 431

Fixed DMD1.058 and DMD2.043.