Stop completely ignoring many Doxygen comments.

For some reason, Doxygen comments such as @class or @enum were considered to
be "structural" (whatever this means) and completely removed during the
parsing time. This is wrong as such comments can be attached to their
corresponding declarations and while it would be arguably better to check that
this is indeed the case (e.g. "@class Foo" really appears before or after the
declaration of this class), throwing them away is definitely not the right
thing to do and keeping them without any further checks is a better alternative.

Examples/test-suite/doxygen_translate_all_tags.i

@@ -396,16 +396,4 @@ int func10(int a, float b)
 {
 }
 
-
-/**
- * \interface someInterface someHeader.h "Header name"
- *
- * Because of structural Doxygen command at the start of comment block,
- * the whole comment block is ignored. See parser.y, f. isStructuralDoxygen()
- * or documentation for the list of commands.
- */
-int func11(int a, float b)
-{
-}
-
 %}

Source/CParse/parser.y

@@ -73,34 +73,23 @@ int isStructuralDoxygen(String *s){
 	  "callgraph",
 	  "callergraph",
 	  "category",
-	  "class",
 	  "def",
 	  "defgroup",
 	  "dir",
-	  "enum",
 	  "example",
 	  "file",
-	  "fn",
 	  "headerfile",
-	  "hideinitializer",
-	  "interface",
 	  "internal",
 	  "mainpage",
 	  "name",
-	  "namespace",
 	  "nosubgrouping",
 	  "overload",
 	  "package",
 	  "page",
-	  "property",
 	  "protocol",
 	  "relates",
 	  "relatesalso",
 	  "showinitializer",
-	  "struct",
-	  "typedef",
-	  "union",
-	  "var",
 	  "weakgroup",
 	};