Maritime Weather+ 6

small changes that do not affect gameplay, matching the recent cleanup initiated in the vanilla-compatible, Static Weather alternative version.

• updated pedia art & text
• updated weather malus promo icon
• removed old (unused) .dds files and orphan DB entries from pre-standalone era
• added compatibility for planned add-on

• promos now affected by storms:
  • weather sensitivity (added to all air units): -20% attack in plot
  • hover unit: -20% CS in plot
  • recon experience: +1 move
  • embark (all variants): +1 move
  • navigator II & frogman: double move (ie half move cost)
• additional user options to control storm despawns over land (default 0% in fresh water, 5% in coastal, 15% inland)
• storm update frequency option now set to game speed ie storms only spawn/move/despawn every few turns (can set back to every turn if desired, see top of MBweather.lua)
• city build block disabled
• better code for table management (tracking tables will no longer fill endlessly with nil entities)
• (-1 movesChange added to plot but not working due to bug in VP, reported on github)

sorry to anyone that started new game on last version -- problems for poly mainly, and also discovered other means of improving the mod:

• 'storm fixer' function, intended to correct bug in civ 5/vp pre-astro ocean movement when features are present, was fixing units it shouldn't. fixed.
• storms can now move over resources
• submarine should be immune to storm movement cost
• hover units should have extra move cost in storm

• simplified build override to mitigate possible interference with AI build logic
• disable (default) road pillage chance in storm plot, fixed pillage in city when enabled (see useroptions)
• allow storm to move over empty hills
• adjust season length, spawn value defaults to be responsive to (more) map settings