Merge pull request #91 from mosra/bc7m6-tables-optional

Don't require the huge BC7m6 tables if this format is disabled
diff --git a/transcoder/basisu_transcoder.cpp b/transcoder/basisu_transcoder.cpp
index ddaf949..79a0560 100644
--- a/transcoder/basisu_transcoder.cpp
+++ b/transcoder/basisu_transcoder.cpp
@@ -146,7 +146,9 @@
 
 namespace basist
 {
+#if BASISD_SUPPORT_BC7_MODE6_OPAQUE_ONLY
 #include "basisu_transcoder_tables_bc7_m6.inc"
+#endif
 
 #if BASISD_ENABLE_DEBUG_FLAGS
 	static uint32_t g_debug_flags = 0;