ENH: Cleanup Find* modules with new HINTS feature

- The find_* commands now provide a HINTS option.
  - The option specifies paths to be preferred over the system paths.
  - Many Find* modules were using two find calls with NO_DEFAULT_PATH
    to approximate the behavior, but that blocked users from overriding
    things with CMAKE_PREFIX_PATH.
  - This commit uses the HINTS feature to get desired behavior in
    only one find command call.

Modules/FindLua51.cmake

@@ -13,13 +13,9 @@
 
 
 FIND_PATH(LUA_INCLUDE_DIR lua.h
-  PATHS
+  HINTS
   $ENV{LUA_DIR}
-  NO_DEFAULT_PATH
   PATH_SUFFIXES include/lua51 include/lua5.1 include/lua include
-)
-
-FIND_PATH(LUA_INCLUDE_DIR lua.h
   PATHS
   ~/Library/Frameworks
   /Library/Frameworks
@@ -29,19 +25,13 @@ FIND_PATH(LUA_INCLUDE_DIR lua.h
   /opt/local # DarwinPorts
   /opt/csw # Blastwave
   /opt
-  PATH_SUFFIXES include/lua51 include/lua5.1 include/lua include
 )
 
 FIND_LIBRARY(LUA_LIBRARY 
   NAMES lua51 lua5.1 lua
-  PATHS
+  HINTS
   $ENV{LUA_DIR}
-  NO_DEFAULT_PATH
-    PATH_SUFFIXES lib64 lib
-)
-
-FIND_LIBRARY(LUA_LIBRARY
-  NAMES lua51 lua5.1 lua
+  PATH_SUFFIXES lib64 lib
   PATHS
   ~/Library/Frameworks
   /Library/Frameworks
@@ -51,7 +41,6 @@ FIND_LIBRARY(LUA_LIBRARY
   /opt/local
   /opt/csw
   /opt
-    PATH_SUFFIXES lib64 lib
 )
 
 IF(LUA_LIBRARY)