Tweak menu spacing and appearance

[jonbrett]

Whilst issue #3 made the menu readable again using the default cinnamon menu styles it's still not quite there.

• Too much spacing around the "HamsterBox" Entry element
• Text Entry element could have a slightly different background
• When "Todays activities" is empty, it still takes up space
• Add some nicer styling to the activity tags in "Todays activities"
• Make today's totals right-aligned

We'll probably need to go back to an applet-specific stylesheet.css to get these right. This should be a minimal as possible to make sure that the applet plays nicely with different themes.

[ghost]

1. -(wontfix) Too much spacing around the "HamsterBox" Entry element
2. Text Entry element could have a slightly different background
3. - X When "Todays activities" is empty, it still takes up space
4. Add some nicer styling to the activity tags in "Todays activities"
5. Make today's totals right-aligned

For number 3 I removed the totals when no today activities are available witch make it look like a spacer instead of an empty list. But I will let the space here as it's the default behaviour of Scroll Box element to have a minimal space to grab the scroll bar, Im scared that If override it, it might cause problem on some themes.

[ghost]

https://imgur.com/a/6aIAO

[elbenfreund]

As this Issue documents the cinnamon applet is now maintained by the Mint Linux team.
As such this repository is kept around for historical and migration reasons.
Contributors are encouraged to head over there and no work will be done on this
repository at all.
Thanks for your support.