Replace std::to_string() with stringstream to make mingw happy.
Add document outlining compiler support for project.
Fixes plural forms for some holy books.
Merge pull request #8098 from Rivet-the-Zombie/moar-fixes

Fixes plural forms for some holy books.
Merge PR #8097 - mingw and Cygwin workaround
Fixes spelling and grammar for some gunmods.
Merge pull request #8101 from Rivet-the-Zombie/gunmodfixez-yeaaaaaahhhhh!

Fixes spelling and grammar for some gunmods.