Standardize header names and file locations

This is both a really big and a really small commit. It is small in
that it only contains renaming, moving and modification of include
directives caused by this.

It is really big in the obvious way of touching something like 200
files.

The new rules for naming files is simple: headers use the `.hpp`
extension. The rules for physical file layout is still kinda in
progress, but the basics are also simple:
 * Significant parts of functionality get their own subfolder
   * Benchmarking is in `catch2/benchmark`
   * Matchers are in `catch2/matchers`
   * Generators are in `catch2/generators`
   * Reporters are in `catch2/reporters`
   * Baseline testing facilities are in `catch2/`
 * Various top level folders also contain `internal` subfolder,
   with files that users probably do not want to include directly,
   at least not until they have to write something like their own
   reporter.
    * The exact files in these subfolders is likely to change later
      on

Note that while some includes were cleaned up in this commit, it
is only the low hanging fruit and further cleanup using automatic
tooling will happen later.

Also note that various include guards, copyright notices and file
headers will also be standardized later, rather than in this commit.

src/catch2/internal/catch_common.hpp

@@ -0,0 +1,89 @@
+/*
+ *  Created by Phil on 29/10/2010.
+ *  Copyright 2010 Two Blue Cubes Ltd. All rights reserved.
+ *
+ *  Distributed under the Boost Software License, Version 1.0. (See accompanying
+ *  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+ */
+#ifndef TWOBLUECUBES_CATCH_COMMON_H_INCLUDED
+#define TWOBLUECUBES_CATCH_COMMON_H_INCLUDED
+
+#include <catch2/internal/catch_compiler_capabilities.hpp>
+
+#define INTERNAL_CATCH_UNIQUE_NAME_LINE2( name, line ) name##line
+#define INTERNAL_CATCH_UNIQUE_NAME_LINE( name, line ) INTERNAL_CATCH_UNIQUE_NAME_LINE2( name, line )
+#ifdef CATCH_CONFIG_COUNTER
+#  define INTERNAL_CATCH_UNIQUE_NAME( name ) INTERNAL_CATCH_UNIQUE_NAME_LINE( name, __COUNTER__ )
+#else
+#  define INTERNAL_CATCH_UNIQUE_NAME( name ) INTERNAL_CATCH_UNIQUE_NAME_LINE( name, __LINE__ )
+#endif
+
+#include <iosfwd>
+#include <string>
+#include <cstdint>
+
+// We need a dummy global operator<< so we can bring it into Catch namespace later
+struct Catch_global_namespace_dummy {};
+std::ostream& operator<<(std::ostream&, Catch_global_namespace_dummy);
+
+namespace Catch {
+
+    struct CaseSensitive { enum Choice {
+        Yes,
+        No
+    }; };
+
+    class NonCopyable {
+        NonCopyable( NonCopyable const& )              = delete;
+        NonCopyable( NonCopyable && )                  = delete;
+        NonCopyable& operator = ( NonCopyable const& ) = delete;
+        NonCopyable& operator = ( NonCopyable && )     = delete;
+    protected:
+        NonCopyable() noexcept = default;
+    };
+
+    struct SourceLineInfo {
+
+        SourceLineInfo() = delete;
+        constexpr SourceLineInfo( char const* _file, std::size_t _line ) noexcept:
+            file( _file ),
+            line( _line )
+        {}
+
+        SourceLineInfo( SourceLineInfo const& other )            = default;
+        SourceLineInfo& operator = ( SourceLineInfo const& )     = default;
+        SourceLineInfo( SourceLineInfo&& )              noexcept = default;
+        SourceLineInfo& operator = ( SourceLineInfo&& ) noexcept = default;
+
+        bool operator == ( SourceLineInfo const& other ) const noexcept;
+        bool operator < ( SourceLineInfo const& other ) const noexcept;
+
+        char const* file;
+        std::size_t line;
+    };
+
+    std::ostream& operator << ( std::ostream& os, SourceLineInfo const& info );
+
+    // Bring in operator<< from global namespace into Catch namespace
+    // This is necessary because the overload of operator<< above makes
+    // lookup stop at namespace Catch
+    using ::operator<<;
+
+    // Use this in variadic streaming macros to allow
+    //    >> +StreamEndStop
+    // as well as
+    //    >> stuff +StreamEndStop
+    struct StreamEndStop {
+        std::string operator+() const;
+    };
+    template<typename T>
+    T const& operator + ( T const& value, StreamEndStop ) {
+        return value;
+    }
+}
+
+#define CATCH_INTERNAL_LINEINFO \
+    ::Catch::SourceLineInfo( __FILE__, static_cast<std::size_t>( __LINE__ ) )
+
+#endif // TWOBLUECUBES_CATCH_COMMON_H_INCLUDED
+