Allow for filtering the main chart by a time period

[coreystone]

The chart works well, but I have a few select measurements from a few years ago that skew my chart and make it really difficult to see my more recent progress. This makes it so that a couple of measurements from several years ago dominate the chart while dozens of recent measurements are very hard to look at closely, and it's harder to understand my progress in the shorter term (over a month, e.g.).

I think some sort of method to filter the chart to allow viewing only recent measurements would fix this.
For example, only show measurements in: the last week, two weeks, month, year, and even a custom range that the user provides.

The argument could be made that users shouldn't be importing one-off measurements from a long time ago with no other consistent measurements, but I think it's important to see long term progress even if it wasn't consistently measured, so a feature like this could make this more useful.

The behavior I'm talking about is seen below, where the impact of more frequent, recent measurements is hard to understand because older measurements take precedence.

[braniii]

@coreystone a more detailed answer will (or might) follow at some point. For now, did you try double tap on the graph? By doing so you should be able to rotate through the available zoom modes. In general, the graph should be interactive. However, I have to say that it barely works. But #192 might solve that.

[coreystone]

I didn't realize that was an available feature, which is basically what I was looking for. You're right that it is kind of slow and could be improved, but it's nice to have. Thank you.