Throw a runtime_error exception for start/stop
Throw a runtime_error exception for start/stop

Throwing a runtime_error exception after Timer::Start or Timer::Stop has been called twice.
darcyliu/mlpack,ajjl/mlpack,palashahuja/mlpack,ranjan1990/mlpack,darcyliu/mlpack,stereomatchingkiss/mlpack,palashahuja/mlpack,ajjl/mlpack,theranger/mlpack,palashahuja/mlpack,ranjan1990/mlpack,ajjl/mlpack,stereomatchingkiss/mlpack,theranger/mlpack,theranger/mlpack,ranjan1990/mlpack,darcyliu/mlpack,stereomatchingkiss/mlpack