Add support for retrieving a filtered view of entries

[aismail]

Why

Sometimes, for analysis purposes, we want to extract a filtered view of a food log. For example, I want to be able to filter only those entries that correspond to sweets, that can be had at all meals. Or maybe I want to see how many bread-related products I am eating.

What

• get_date method from Client receives filter as a parameter. It is a function which takes one parameter of type myfitnesspal.entry.Entry and returns True/False depending on whether the entry is added or not

  Note

This is not exactly the ideal solution. The ideal solution is to make the Day / Meal / Entry structures mutable. However, for me that is too much work right now.

[coddingtonbear]

Hey there @aismail; could I convince you into filing a pull request with the changes you posted in your 8-filtered-view-of-entries branch? Having just glanced at those changes, they look like they'll work great, and I'm not sure if you were planning on adding additional features.

If you're not familiar with how a pull request works: you just click the "New Pull Request" button on https://github.com/coddingtonbear/python-myfitnesspal and select your branch name (8-filtered-view-of-entries branch) when prompted.

Cheers!