Allow user-defined headers

[mgalloy]

IDLdoc should allow unrecognized headers as standard file/routine attributes and pass them through into the documentation. This request was originally from #51.

[mgalloy]

Author: APanasenco I think this is ''already'' implemented, no?

Something like this:

;+
; ===This is a non-standard header.===
; Some ASCII art goes here.
;            (too lazy to google for some)
;-

;+
;This is a non-standard function/procedure attribute header thing
;It can have some descriptions
;Two men walk into a bar
;  SOMEFUNCTION
; Parameters:
;            SOMEPARAMETERS
;                     INCREDIBLY LONG MODIFICATION LIST
;      *****************
; ----------
; ()()()
;-
function SOMEFUNCTION, SOMEPARAMETER
    return, SOMEVALUE
end

...works as well as it can. The file header is placed under the file name, and the function header is placed under the syntax.

Unless, of course, the ticket is talking about line concatenation that occurs...