Resolve "Clean / move some code"

Closes #35

See merge request !31

Resolve "Improve "discoveries" chart"

Closes #34

See merge request !30

Resolve "Fix/improve charts display"

Closes #32

See merge request !29

Resolve "Add "top artists" chart"

Closes #17

See merge request !25

Resolve "Split global / period statistics"

Closes #31

See merge request !26

Resolve "Allow navigation with swipe"

Closes #30

See merge request !24

Resolve "Add navigation bottom bar"

Closes #29

See merge request !23

Resolve "Improve layout"

Closes #20

See merge request !22

Resolve "Add "discoveries" charts"

Closes #14

See merge request !21

Resolve "Remove tooltips on charts"

Closes #28

See merge request !20

Resolve "Use date range in global stats API call"

Closes #27

See merge request !19

Resolve "Stack global counts and eclecticism charts"

Closes #26

See merge request !18

Resolve "Add "%" on repartition charts"

Closes #25

See merge request !17

Resolve "Compute gradient color from bar height"

Closes #22

See merge request !16

Resolve "Merge charts code"

Closes #23

See merge request !15

Resolve "Add titles on both sides of charts"

Closes #21

See merge request !14

Resolve "Improve charts colors"

Closes #19

See merge request !13

Resolve "Add refresh button"

Closes #12

See merge request !12

Resolve "Add "scrobbles / hour" chart"

Closes #16

See merge request !10

Resolve "Add "scrobbles / day" chart"

Closes #15

See merge request !9