Add userTime and kernelTime in CpuSampleModel, support sorting by time in analyzers

[303248153]

There should be a weight in each sample like user time, kernel time and total time, for now the weight of all samples is 1, that mean the profiler can't found which function really do the heavy things. reference: https://gist.github.com/303248153/b4164b9cb812b9f02df8d1601300be71