Add codecov.io coverage collection from AppVeyor

Also had to add new project to redirect CTest output, add
separate batch scripts for AppVeyor because it doesn't handle
multi-line batch scripts in yaml properly, and other helper
scripts.

misc/appveyorTestRunScript.bat

@@ -0,0 +1,11 @@
+cd Build
+if "%CONFIGURATION%"=="Debug" (
+  echo "appveyorTestScript.bat thinks this is a Debug build"
+  ctest -j 2 -C %CONFIGURATION% -D ExperimentalMemCheck
+  python ..\misc\appveyorMergeCoverageScript.py
+  codecov --root .. --no-color --disable gcov -f cobertura.xml -t %CODECOV_TOKEN%
+)
+if "%CONFIGURATION%"=="Release" (
+  echo "appveyorTestScript.bat thinks this is a Release build"
+  ctest -j 2 -C %CONFIGURATION%
+)