[PATCH] [clang-tidy] Add support for custom configuration file names/formats.

[Daniel Jasper]

Looks good.

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Comment at: clang-tidy/ClangTidyOptions.cpp:183
@@ -173,3 +182,3 @@
     if (!Result)
-      Result = TryReadConfigFile(CurrentPath);
+        Result = TryReadConfigFile(CurrentPath);
 
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indentation

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Comment at: clang-tidy/ClangTidyOptions.h:144
@@ +143,3 @@
+  /// return llvm::make_unique<FileOptionsProvider>(GlobalOptions,
+  ///     DefaultOptions, OverrideOptions, ConfigHandlers);
+  /// \endcode
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It seems complicated to have to specify all of GlobalOptions, DefaultOptions and OverrideOptions. Consider adding overloads or something.

nit: indentation ;-)

http://reviews.llvm.org/D5821