add @nogc and vector mangling
Detab file.
Fix Issue 12607 - Document that IUnknown classes must mark toString with extern(D) when overriding it.
Merge pull request #542 from WalterBright/add-nogc

add @nogc and vector mangling
Merge pull request #543 from AndrejMitrovic/Fix12607

Issue 12607 - Document that IUnknown classes must mark toString with extern(D) when overriding it
Add intro.dd to makefiles

Add intro.dd to lists just as the other .dd files.
This page had been generated years ago, and in D1 currently.
Add intro.html to indexes

Add Introduction page to both the navigation and the language spec
contents.
Merge pull request #544 from qchikara/ReviveIntroPage

Issue 12535: Fix link to the Introduction page
Update ZeroBUGS debugger link.
Detab file.
Fix Issue 12005 - Add a link to the DWiki for open-source ddoc-based documentation generators.
Merge pull request #549 from AndrejMitrovic/Fix12005

Issue 12005 - DDoc example refers to a dead project
Merge pull request #546 from AndrejMitrovic/Fix12538

Update ZeroBUGS debugger link.