This adds copyright/license notification blocks CMake's find-modules.
Many of the modules had no notices at all. Some had notices referring
to the BSD license already. This commit normalizes existing notices and
adds missing notices.
- 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.
BUG: FindSDL now has flag it responds to so it will not find/link against SDLmain. This is required to build libraries instead of applications since they don't have main().
ENH: All modules have a predictable search order, where environmental variables are searched before system paths. This is designed to make automation easier for those that need to automatically build projects without intervention but may be using alternative install locations for isolated testing.
ENH: New modules for OpenSceneGraph, Freetype, GDAL, Lua, QuickTime, GIFLIB, Producer, OpenThreads.
STYLE: Added documentation explaining peculuar SDL_LIBRARY_TEMP variable in SDL
module when library find is incomplete.
