Bunch of CMake fixes

* Add more Git ignore patterns
* Fix Ogg dependency handling (closes #203)
* Remove unneeded compiler flag (closes #204)
* Fix Visual Studio DLL build error error C2491:
  'flac_internal_rename_utf8': definition of dllimport function not
  allowed (closes #205)
* Add alias targets
* Reduce number of CMake files
* Improve CMake intrinsics detection
diff --git a/Makefile.am b/Makefile.am
index ce4519f..33bc679 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -41,7 +41,7 @@
 	CMakeLists.txt \
 	config.cmake.h.in \
 	flac-config.cmake.in \
-	cmake/FindOGG.cmake \
+	cmake/FindOgg.cmake \
 	cmake/UseSystemExtensions.cmake \
 	COPYING.FDL \
 	COPYING.GPL \