#2 GRIB file navigation needs improvement

[Gabriel Galibourg]

GRIB file navigation needs improvement:

1) Create tab navigation for each GRIB file

2) On the left navigation pane:
Cut it in two (upper and lower section)
In the upper show the GRIB variables
In the lower section show the forecast times

Remember as much as possible (eg var and time) when
navigating to another GRIB file.