Example usage of this module:
```
import benchmark
mut bmark := benchmark.new_benchmark()
// by default the benchmark will be verbose, i.e. it will include timing information
// if you want it to be silent, set bmark.verbose = false
for {
   bmark.step() // call this when you want to advance the benchmark.
                // The timing info in bmark.step_message will be measured starting from the last call to bmark.step
   ....

   //bmark.fail() // call this if the step failed
   //bmark.step_message(('failed')

   bmark.ok() // call this when the step succeeded
   println( bmark.step_message('ok')
}
bmark.stop() // call when you want to finalize the benchmark
println( bmark.total_message('remarks about the benchmark') )
```

benchmark.start() and b.measure() are convenience methods,
intended to be used in combination. Their goal is to make
benchmarking of small snippets of code as *short*, easy to
write, and then to read and analyze the results, as possible.
Example:
```v
import benchmark
b := benchmark.start()

// your code 1 ...
b.measure('code_1')

// your code 2 ...
b.measure('code_2')
```
... which will produce on stdout something like this:
SPENT    17 ms in code_1
SPENT   462 ms in code_2