moved into fsleyes

Enh/platform

See merge request fsl/fsleyes/widgets!60

Enh/textbmp

See merge request fsl/fsleyes/widgets!58

fontSize/width/height - as long as at least one of fontSize or height is
specified, the other parameters will be inferred. Also fixed documentation -
returned array is (h, w, 4), not (w, h, 4)

Enh/floatspin

See merge request fsl/fsleyes/widgets!54

Bf/autotextctrl

See merge request fsl/fsleyes/widgets!53

uiactionsim is fixed

Enh/status clearthread die

See merge request fsl/fsleyes/widgets!50