Allow Range field on weapons to be altered by features

[richardwilkes]

Examples of data found in this field that don't fit the usual pattern:

"range": "×2",
"range": "1,000/3,000 mi.",
"range": "1-6",
"range": "1/10",
"range": "1/2D 5, Max 10",
"range": "1/3 mi.",
"range": "5/point",
"range": "5mi",
"range": "B550",
"range": "C/1",
"range": "PBAoE 2",
"range": "ST + Skill/5",
"range": "ST + skill/5",
"range": "ST/2 + skill/5",
"range": "STx2.5",
"range": "Sight",
"range": "Within Sight",
"range": "max 100",
"range": "spec",
"range": "spec.",