Shields/Mapview Improvements

[cockroachking]

In this pull request:

• Added the wide4 template for mara to close out Morocco shield mara 2-digit missing #966
• Updated the Seaway Trail shield (thanks to @mapcat)
• Added the option to set traveled/untraveled routes to be transparent (rather than disappearing, which seems to be the end goal) in mapview.php as an initial attempt at improving Option to show/hide traveled/untraveled segments in Mapview #771
• Added a new TMblack in the custom color array as another option for users. (I prefer black to purple for Tier 4, so I'm making the URLs I use a little shorter.)

These changes, especially the mapview stuff, should definitely have a brief tenure on TMstage to make sure they are working as intended.

[jteresco]

On its way to tmstage.

[jteresco]

Now on the main site.