Fix the travis linking issue with cmake and g++-4.7.

This explicitly adds the dependencies to wesnoth to control the order
of the linking in order to avoid linker errors due to parameter order.

Also take out -O parameter to the cmake build as it's not used since
cmake has its own settings for a release build.

.travis.yml

@@ -13,7 +13,7 @@ env:
     - OPT=-O2 CXXSTD=11 NLS=false
     - OPT=-O2 CXXSTD=1y NLS=false
     - NLS=true
-    - OPT=-O0 CXXSTD=11 NLS=false USE_CMAKE=true
+    - CXXSTD=11 NLS=false USE_CMAKE=true
 matrix:
   exclude:
     - compiler: gcc

src/CMakeLists.txt

@@ -1124,6 +1124,9 @@ if(ENABLE_GAME)
 			wesnoth-gui_widget_definition
 			wesnoth-gui1_widgets
 			wesnoth-schema_validator
+			wesnoth-core
+			wesnoth-lua
+			wesnoth-game
 			wesnoth-sdl
 		)
 	else(ENABLE_TESTS)