io includes clean up - unwanted removed others shifted to .cpp file.

Error in build log fixed

squash of previous two commits

Build log errors fixed 2

squash - 2

Build log error fix.

squash 3
Merge pull request #2653 from srgnuclear/ioincludes

io includes clean up - unwanted removed others shifted to .cpp file.
add light-scrubber.sh to scripts
fixed light-scrubber.sh
add GPLv3 text for distro-packaging
Merge pull request #2649 from sanuj/feature/SGVector_cleanup

Move mean/linspace from SGVector to CStatistics/CMath respectively
respect system's or distribution's C[XX]FLAGS
Merge pull request #2655 from besser82/system-flags

respect system's or distribution's C[XX]FLAGS
defer SWIG-related processing after libshogun is build
fix r_modular install
added option to disable HDF5 even when available
Merge pull request #2656 from karlnapf/develop

added option to disable HDF5 even when available
Transfer sorting functions from SGVector to CMath