Initial commit

added libraries:
opus
flac
libsndfile

updated:
libvorbis
libogg
openal

- Everything works as expected for now. Bare in mind libsndfile needed the check for whether or not it could find the xiph libraries removed in order for this to work.

Engine/lib/flac/cmake/UseSystemExtensions.cmake

@@ -0,0 +1,63 @@
+include(CheckCSourceCompiles)
+
+check_c_source_compiles("
+    #include <wchar.h>
+    mbstate_t x;
+    int main() { return 0; }"
+    HAVE_MBSTATE)
+if(NOT HAVE_MBSTATE)
+    check_c_source_compiles("
+        #define _XOPEN_SOURCE 500
+        #include <wchar.h>
+        mbstate_t x;
+        int main() { return 0; }"
+        DODEFINE_XOPEN_SOURCE)
+endif()
+check_c_source_compiles("
+    #define __EXTENSIONS__ 1
+    #include <stdio.h>
+    #ifdef HAVE_SYS_TYPES_H
+    # include <sys/types.h>
+    #endif
+    #ifdef HAVE_SYS_STAT_H
+    # include <sys/stat.h>
+    #endif
+    #ifdef STDC_HEADERS
+    # include <stdlib.h>
+    # include <stddef.h>
+    #else
+    # ifdef HAVE_STDLIB_H
+    #  include <stdlib.h>
+    # endif
+    #endif
+    #ifdef HAVE_STRING_H
+    # if !defined STDC_HEADERS && defined HAVE_MEMORY_H
+    #  include <memory.h>
+    # endif
+    # include <string.h>
+    #endif
+    #ifdef HAVE_STRINGS_H
+    # include <strings.h>
+    #endif
+    #ifdef HAVE_INTTYPES_H
+    # include <inttypes.h>
+    #endif
+    #ifdef HAVE_STDINT_H
+    # include <stdint.h>
+    #endif
+    #ifdef HAVE_UNISTD_H
+    # include <unistd.h>
+    #endif
+    int main() { return 0; }"
+    DODEFINE_EXTENSIONS)
+
+add_definitions(
+    -D_DARWIN_C_SOURCE
+    -D_POSIX_PTHREAD_SEMANTICS
+    -D__STDC_WANT_IEC_60559_BFP_EXT__
+    -D__STDC_WANT_IEC_60559_DFP_EXT__
+    -D__STDC_WANT_IEC_60559_FUNCS_EXT__
+    -D__STDC_WANT_IEC_60559_TYPES_EXT__
+    -D__STDC_WANT_LIB_EXT2__
+    -D__STDC_WANT_MATH_SPEC_FUNCS__
+    -D_TANDEM_SOURCE)