Split appveyor build scripts into parts so they don't error out from being too big.

appveyor.yml → dlib/appveyor/dtest.yml

@@ -7,7 +7,7 @@ build_script:
   - mkdir %APPVEYOR_BUILD_FOLDER%\build_test
   - cd %APPVEYOR_BUILD_FOLDER%\build_test
   - cmake -G "Visual Studio 14 2015 Win64" -T host=x64 ../dlib/test
-  - cmake --build . --config %CONFIGURATION% 
+  - cmake --build . --config %CONFIGURATION% --target dtest
 
 test_script:
   # run test

dlib/appveyor/examples.yml

+version: "{build}"
+
+configuration: Release
+
+build_script:
+  # build test
+  - mkdir %APPVEYOR_BUILD_FOLDER%\build_examples
+  - cd %APPVEYOR_BUILD_FOLDER%\build_examples
+  - cmake -G "Visual Studio 14 2015 Win64" -T host=x64 ../examples
+  - cmake --build . --config %CONFIGURATION% 
+
+test_script:
+  # run test