Cleaned up some linalg patches. Added no_diag param to linalg::sum. I tried to replace some sgvector and old linalg methods with new ones. However, the new methods lead to tons of warnings and the compile is extremely slow, as I mentioned in #3399.
Cleaned up Any and SGObject serialization. Had SGVector serialization working at local but not on Travis. I just download docker and it is still pulling shogun/dev. Will update docs in SGObject and try to figure out the travis issue tmr.
