Improve anchors for ddoc (dlang.org)

[Martin Nowak]

Basically every caption in the language reference should have an anchor
so that one can refer to it.

http://www.dlang.org/template.html#class-templates    // <- missing
https://github.com/D-Programming-Language/d-programming-language.org/blob/master/template.dd#L749

http://www.dlang.org/template.html#function-templates
https://github.com/D-Programming-Language/d-programming-language.org/blob/master/template.dd#L805


For the library reference different scoped members with same names collide.
http://www.dlang.org/phobos/std_range.html#popFront

Listing a flat popFront in the jump-to header is pretty useless.
Each entry that has more than one member could have it's own jump-to.

std.range

Jump to: RangeA, RangeB, ...

...

struct RangeA;
-----------------------------
Jump to: front, popFront, ...