Enable more warnings and squash them

CMakeLists.txt

frustmag/CMakeLists.txt

frustmag/include/tksvm/frustmag/element_policy/single.hpp

frustmag/include/tksvm/frustmag/observables.hpp

frustmag/include/tksvm/frustmag/update/global_trafo.hpp

frustmag/include/tksvm/frustmag/update/heatbath.hpp

frustmag/include/tksvm/frustmag/update/overrelaxation.hpp

gauge/CMakeLists.txt

gauge/src/gauge_sim.cpp

include/argh.h

include/tksvm/phase_space/sweep.hpp

include/tksvm/phase_space/sweep/policy.hpp

include/tksvm/phase_space/sweep/sweep_grid.hpp

include/tksvm/sim_adapters/pt_adapter.hpp

include/tksvm/utilities/mpi/dispatcher.hpp

ising/CMakeLists.txt

svm