Bugfix: compilation was not working on recent 64-bit Ubuntu versions.

This patch addresses two 64-bit platform compilation issues:
- Force 32-bit mode for gcc using '-m32'
- Recent library modifications broke the 32-bit compilation on 64-bit machines: updated
  'compile.txt' to include the need for the 'gcc-multilib' package.

src/BuildUnix-Win32.cmake

@@ -15,7 +15,7 @@ set (CMAKE_SHARED_LIBRARY_LINK_C_FLAGS)	# to get rid of -rdynamic
 set (CMAKE_C_FLAGS "-DFORWINDOWS")
 
 # Static where possible (i.e. only not on the APPLE)
-set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -static")
+set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -static -m32")
 
 set (scythername "scyther-w32.exe")
 add_executable (${scythername} ${Scyther_sources})

src/BuildUnix.cmake

@@ -9,7 +9,7 @@
 message (STATUS "Building Linux version")
 
 # Static where possible (i.e. only not on the APPLE)
-set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -static")
+set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -static -m32")
 
 set (scythername "scyther-linux")
 add_executable (${scythername} ${Scyther_sources})

src/compile.txt

@@ -21,6 +21,9 @@ Needed:
   [cmake]
 	A Makefile generator, available on almost any platform.
 
+  [gcc-multilib]
+	Some 64-bit platforms need this to enable 32-bit compilation.
+
 
 For cross-compilation (Windows):