use explicit file paths for CMake rather then globing, This is recommended by cmake devs.

globbing vs explicit is discussed here.
http://www.cmake.org/pipermail/cmake/2008-December/025694.html

Practical implications are:
- developers need to keep CMakeLists.txt files up to date.
- Users wont get strange linking errors if they build after a file is added, since CMake detects CMakeLists.txt is modified and automatically reconfigure.

extern/lzma/CMakeLists.txt

@@ -24,8 +24,16 @@
 #
 # ***** END GPL LICENSE BLOCK *****
 
-SET(INC . )
+SET(INC
+	.
+)
 
-FILE(GLOB SRC ./*.c)
+SET(SRC
+	Alloc.c
+	LzFind.c
+	LzmaDec.c
+	LzmaEnc.c
+	LzmaLib.c
+)
 
 BLENDERLIB(extern_lzma "${SRC}" "${INC}")