refactor SDE detection in cmake files (#4512,#4700)

- add a specific plugin configuration
- checks for sde,sg and pe libs, adds pthread,socketi and dl if found
- adds #define SDE64 on 64 bit platforms
add missing file
restore submodule version
Merge pull request #4521 from tbonfort/cmake-sde

Building SDE support on 64-bit Linux needs work.