Add support for templated tests

This adds support for templated tests and test methods via
`TEMPLATE_TEST_CASE` and `TEMPLATE_TEST_CASE_METHOD` macros. These
work mostly just like their regular counterparts*, but take an
unlimited** number of types as their last arguments.

* Unlike the plain `TEST_CASE*` macros, the `TEMPLATE*` variants
require a tag string.

** In practice there is limit of about 300 types.

projects/SelfTest/UsageTests/Misc.tests.cpp

@@ -261,6 +261,46 @@ TEST_CASE( "vectors can be sized and resized", "[vector]" ) {
     }
 }
 
+TEMPLATE_TEST_CASE( "TemplateTest: vectors can be sized and resized", "[vector][template]", int, float, std::string, (std::tuple<int,float>) ) {
+
+    std::vector<TestType> v( 5 );
+
+    REQUIRE( v.size() == 5 );
+    REQUIRE( v.capacity() >= 5 );
+
+    SECTION( "resizing bigger changes size and capacity" ) {
+        v.resize( 10 );
+
+        REQUIRE( v.size() == 10 );
+        REQUIRE( v.capacity() >= 10 );
+    }
+    SECTION( "resizing smaller changes size but not capacity" ) {
+        v.resize( 0 );
+
+        REQUIRE( v.size() == 0 );
+        REQUIRE( v.capacity() >= 5 );
+
+        SECTION( "We can use the 'swap trick' to reset the capacity" ) {
+            std::vector<TestType> empty;
+            empty.swap( v );
+
+            REQUIRE( v.capacity() == 0 );
+        }
+    }
+    SECTION( "reserving bigger changes capacity but not size" ) {
+        v.reserve( 10 );
+
+        REQUIRE( v.size() == 5 );
+        REQUIRE( v.capacity() >= 10 );
+    }
+    SECTION( "reserving smaller does not change size or capacity" ) {
+        v.reserve( 0 );
+
+        REQUIRE( v.size() == 5 );
+        REQUIRE( v.capacity() >= 5 );
+    }
+}
+
 // https://github.com/philsquared/Catch/issues/166
 TEST_CASE("A couple of nested sections followed by a failure", "[failing][.]") {
     SECTION("Outer")