Edit download function

- update urls
- download files separate
- add md5 test function to download function, remove from build
- add extract function to download function, remove from build
- add patch function to download function, remove from build
Update build and patch system

- update all build functions for an easier maintenance
- update patch system: apply several patches in patch dir
- add patches
Rearrange source
Edit echo and exit

- Add function which print into log-file and the default I/O
- Remove all echo commands which write into the log-file with print_log
- Add several exit on error function instead use “|| exit 1”
Sync after first build
Test run on clean Mac

- Package manager: only gcc-4.8 and binutil are needed
- Symbolic links to homebrew gcc are not longer needed
- Log dir and log-file must be on top of the function
create_dir_structure
- Build: some modifications on Flags and CC export
- Add patch file for nurses for support of clang 3
Several modifications
Only build gcc for c/c++ and fortran
Rearrange for building several targets
Add build for Raspbian
Finish build 2013.12
Merge branch 'build_2013-12'