[PROPOSAL] Time Series generator

# Time series generator

This issue is a proposal to generate and simulate time serie from a set of sensors.

## Time series generator configuration

Simple configuration to generate time serie with a period of 5 seconds from 2012-04-23T18:25:00.000Z to 2012-04-23T18:25:15.000Z.

```yaml
masks:
- selector:
jsonpath : 'timestamp'
mask:
timeserie:
period: "5s" # 1s by default
from: "2012-04-23T18:25:00.000Z" # current time by default
to: "2012-04-23T18:25:15.000Z" # empty by default that mean endless time serie generator
```

The following command generate timeserie dataset

```console
$ echo '{"timestamp": "" }' | pimo
{"timestamp": "2012-04-23T18:25:00.000Z" }
{"timestamp": "2012-04-23T18:25:05.000Z" }
{"timestamp": "2012-04-23T18:25:10.000Z" }
```

## Multi-Sensors configuration

Timeserie mask is not streamable. It start to generate data after the close of the input stream. Each input line is a sensor configuration and `timeserie` mask generate data for each sensors.

```console
$ echo '{ "id": 1, "timestamp": "" }\n'{"id": 2, "timestamp": "" }' | pimo
{"id": 1, "timestamp": "2012-04-23T18:25:00.000Z" }
{"id": 2, "timestamp": "2012-04-23T18:25:00.000Z" }
{"id": 1, "timestamp": "2012-04-23T18:25:05.000Z" }
{"id": 2, "timestamp": "2012-04-23T18:25:05.000Z" }
{"id": 1, "timestamp": "2012-04-23T18:25:10.000Z" }
{"id": 2, "timestamp": "2012-04-23T18:25:10.000Z" }
```

## Time Serie simulation

If the `simulate` option is activating `timeserie` wait for the period between each data generation.

```yaml
masks:
- selector:
jsonpath : 'timestamp'
mask:
timeserie:
period: "5s" # 1s by default
from: "2012-04-23T18:25:00.000Z" # current time by default
to: "2012-04-23T18:25:15.000Z" # empty by default that mean endless time serie generator
simulate: true # false by default
```

Start by tracing the pimo command's mask configuration and input-stream handling; the payload does not name specific files or tests. Compare the proposed YAML examples with the single-sensor and multi-sensor outputs, including the optional simulation delay. Done means the documented period, from/to bounds, sensor ordering, and simulate behavior work as specified.

Written by the indexing model from the issue text.