general main menu enhancements

[sponnify]

a more fleshed-out main menu would be nice.

• removing beatmaps
• searching for beatmaps
• "sort by" options (name, date, length, no. diffs, highest/lowest sr)

maybe more data attached to beatmaps imported

• date added
• tags that can be added

etc.

[minetoblend]

• removing beatmaps
• searching for beatmaps

This got added in yesterday's update.

• "sort by" options (name, date, length, no. diffs, highest/lowest sr)

This is already supported server side, but still needs a ui for it.

maybe more data attached to beatmaps imported

• date added
• tags that can be added

I already store those two things on import, however they're not being displayed right now (and tags might also be missing during export)