Simplify the main GPU kernel and add another kernel 'k_pair_reneigh'. It works good on GTX1070 (Pascal), but still there is a problem with non-deterministic results on Volta.
I reimplement BaseCharge::compute methods in the child class LJ_TIP4PLong to correctly embed a new kernel in the code.
Also commit includes some codestyle fixes.
Source code, Makefiles and Install for GPU-accelerated TIP4P pair style.
It is implemented as a part of the standard GPU package.
The style is compatible with the standard lj/cut/tip4p/long.
Also, this commit modifies "atom.h" just to
add a getter for variable 'max_same'.
