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/CMakeLists.txt b/CMakeLists.txt
index 8c26b0b..c83dd83 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,7 +23,7 @@
 option(WITH_OGG "ogg support (default: test for libogg)" ON)
 
 if(WITH_OGG)
-    find_package(OGG REQUIRED)
+    find_package(Ogg REQUIRED)
 endif()
 
 find_package(Iconv)
@@ -36,9 +36,6 @@
 if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wcast-align -Wshadow -Wwrite-strings -Wctor-dtor-privacy -Wnon-virtual-dtor -Wreorder -Wsign-promo -Wundef")
 endif()
-if(CMAKE_C_COMPILER_ID MATCHES "GNU")
-    set(CMAKE_EXE_LINKER_FLAGS -no-pie)
-endif()
 
 include(CMakePackageConfigHelpers)
 include(CPack)
@@ -57,7 +54,11 @@
 check_include_file("byteswap.h" HAVE_BYTESWAP_H)
 check_include_file("inttypes.h" HAVE_INTTYPES_H)
 check_include_file("stdint.h" HAVE_STDINT_H)
-check_include_file("x86intrin.h" FLAC__HAS_X86INTRIN)
+if(MSVC)
+    check_include_file("intrin.h" FLAC__HAS_X86INTRIN)
+else()
+    check_include_file("x86intrin.h" FLAC__HAS_X86INTRIN)
+endif()
 
 check_function_exists(fseeko HAVE_FSEEKO)
 
@@ -140,7 +141,6 @@
         FILES
             "${CMAKE_CURRENT_BINARY_DIR}/flac-config.cmake"
             "${CMAKE_CURRENT_BINARY_DIR}/flac-config-version.cmake"
-            "cmake/FindOGG.cmake"
         DESTINATION "${CMAKE_INSTALL_DATADIR}/${PROJECT_NAME}/cmake")
 endif()