Known problems in the time slider

[fergonco]

The time-slider in master has these known problems:

• it does not show any information about the time instances that are available in the slider and it is necessary to start sliding to see how the different positions change the associated label.
• the label shows only month and year, which can be not enough to differentiate two positions.
• the positions in the slider are not proportional
• it is not possible, seeing the slider to know which layers are affected.
• it is difficult to use from a device with small screen since the handler is small. Not easy to change with css.

A different timeslider is provided in the map-ui-merge branch which solves only the proportional positions in the slider.