Support in hasDeclaration for types with getDecl()
    
Using a new metafunction for detecting the presence of the member
'getDecl' in a type T, added support to hasDeclaration for any such type
T. This allows hasDecl() to be replaced and enables several other
subclasses of clang::Type to use hasDeclaration.

Updated unittests and LibASTMatchersReference.html.

Reviewers: klimek


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175532 91177308-0d34-0410-b5e6-96231b3b80d8
Correctly format macro with unfinished template declaration.

We can now format:
  #define A template <typename T>

Before this created a segfault :-/.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175533 91177308-0d34-0410-b5e6-96231b3b80d8
[docs] Revise content on ExternalProjectsUsingClang page.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175534 91177308-0d34-0410-b5e6-96231b3b80d8
[docs] Rename to permit wider variety of  content.

I don't want to rule out the possibility of linking to e.g. interesting
blog posts about uses of Clang, so avoid restricting the content to
"projects".

This breaks URL compatibility, but this document was committed less than
an hour ago so hopefully nobody has linked to it yet.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175535 91177308-0d34-0410-b5e6-96231b3b80d8