Revert "remove miniz and zlib from libzetaglest"

source/shared_lib/CMakeLists.txt

@@ -214,7 +214,28 @@ IF(BUILD_MODEL_VIEWER OR BUILD_MAP_EDITOR OR BUILD_ZETAGLEST)
 		endif()
 	endif()
 
+	message(STATUS "Searching for zlib")
+	include(FindZLIB)
+	IF (FORCE_EMBEDDED_LIBS OR NOT ZLIB_FOUND)
+		SET(DIRS_WITH_SRC
+			${DIRS_WITH_SRC}
+			# miniz is a library included with the ZG distribution. Not as
+			# developed as zlib, but smaller, and uses the same function names
+			# so basically a replacement for miniz. We may one day replace
+			# miniz with the zlib sources
+			miniz)
+	ELSE()
+		if (ZLIB_FOUND)
+			message(STATUS "Using external zlib")
+			SET(EXTERNAL_LIBS ${EXTERNAL_LIBS} ${ZLIB_LIBRARIES})
+			INCLUDE_DIRECTORIES(${ZLIB_INCLUDE_DIRS})
+			add_definitions("-DHAVE_ZLIB")
+		ENDIF()
+	ENDIF()
+
 	SET(DIRS_WITH_SRC
+		${DIRS_WITH_SRC}
+		compression
 		feathery_ftp
 		glew
 		graphics