Cleaned some forecast callbacks

Added js function to move last timestep, put relative paths, added relative humidity to visibility popup if available.

Move floating elements in forecast.py file inside tab_forecast and make...

See merge request !13

# Conflicts:
#   tabs/forecast.py

Remove fullscreen button from map area. Add prevent_initial_call to zoom_country function

See merge request !14

Add remaining changes: Remove 'forecast issued' advisory. Reset width of Views dropup, change z-index for Views dropup so it doesn't overlap copyright, update date url output, and update tests.

Fix navbar centering issue on fullscreen and update tests for modified date formats in forecast file.

Move floating elements in forecast.py file inside tab_forecast and make changes to fix date url functionality

Update date picker to fix error. Adjust scroll wheel sensitivity and make some style updates for forecast page.