Feat: Album year + sorting

[sevonj]

Closes #549

Changes:

• Add year tag to album
• Sort by year in album grid

Comments:

Null is treated as the lowest value in sorting.

[sevonj]

Should be OK now:

• I renamed year to startYear, and added endYear.
• They track minimum and maximum values from the songs.

I spent too much time tearing my hair out trying to figure why this doesn't work, but apparently the app just couldn't parse the year from mp3 files I created for testing. Probably the same issue as #182.

There are further improvements to make, such as displaying the year, and tracking original year, but I'd rather break those into separate issues.

[zyrouge]

Should be OK now:

• I renamed year to startYear, and added endYear.
• They track minimum and maximum values from the songs.

I spent too much time tearing my hair out trying to figure why this doesn't work, but apparently the app just couldn't parse the year from mp3 files I created for testing. Probably the same issue as #182.

There are further improvements to make, such as displaying the year, and tracking original year, but I'd rather break those into separate issues.

The metadata specification is all over the place and ID3v4 should be supported. Open a issue with the file it did not work with and I'll look into it.