Split SelfTest test files into Usage and Introspective varieties

Usage: just exercises Catch. The tests are over arbitrary date/ types
Introspective: Tests parts of Catch itself.

projects/SelfTest/UsageTests/Benchmark.tests.cpp

@@ -0,0 +1,43 @@
+#include "catch.hpp"
+
+#include <map>
+
+TEST_CASE( "benchmarked", "[!benchmark]" ) {
+
+    static const int size = 100;
+
+    std::vector<int> v;
+    std::map<int, int> m;
+
+    BENCHMARK( "Load up a vector" ) {
+        v = std::vector<int>();
+        for(int i =0; i < size; ++i )
+            v.push_back( i );
+    }
+    REQUIRE( v.size() == size );
+
+    BENCHMARK( "Load up a map" ) {
+        m = std::map<int, int>();
+        for(int i =0; i < size; ++i )
+            m.insert( { i, i+1 } );
+    }
+    REQUIRE( m.size() == size );
+
+    BENCHMARK( "Reserved vector" ) {
+        v = std::vector<int>();
+        v.reserve(size);
+        for(int i =0; i < size; ++i )
+            v.push_back( i );
+    }
+    REQUIRE( v.size() == size );
+
+    int array[size];
+    BENCHMARK( "A fixed size array that should require no allocations" ) {
+        for(int i =0; i < size; ++i )
+            array[i] = i;
+    }
+    int sum = 0;
+    for(int i =0; i < size; ++i )
+        sum += array[i];
+    REQUIRE( sum > size );
+}