Add spawnunit wrapper

See #716

scripts/spawnunit.lua

@@ -0,0 +1,57 @@
+-- create unit at pointer or given location
+-- wraps modtools/create-unit.lua
+
+usage = [[Usage:
+- spawnunit RACE CASTE
+- spawnunit RACE CASTE NAME
+- spawnunit RACE CASTE NAME x y z
+- spawnunit RACE CASTE [NAME] [additional arguments]
+    Create a unit
+- spawnunit -help
+    Display this help message
+- spawnunit -command ARGUMENTS
+    Display the command used to invoke modtools/create-unit
+
+additional arguments are passed to modtools/create-unit -
+see "modtools/create-unit -help" for more information.
+]]
+
+function extend(tbl, tbl2)
+    for _, v in pairs(tbl2) do
+        table.insert(tbl, v)
+    end
+end
+
+local show_command = false
+local args = {...}
+local first_arg = (args[1] or ''):gsub('^-*', '')
+if first_arg == 'help' or #args < 2 then
+    print(usage)
+    return
+elseif first_arg == 'command' then
+    show_command = true
+    table.remove(args, 1)
+end
+
+local new_args = {'-race', args[1], '-caste', args[2]}
+if #args == 3 then
+    extend(new_args, {'-nick', args[3]})
+elseif #args == 6 then
+    if tonumber(args[4]) and tonumber(args[5]) and tonumber(args[6]) then
+        extend(new_args, {'-nick', args[3], '-location', '[', args[4], args[5], args[6], ']'})
+    end
+else
+    local start = 3
+    if #args >= 3 and args[3]:sub(1, 1) ~= '-' then
+        extend(new_args, {'-nick', args[3]})
+        start = 4
+    end
+    for i = start, #args do
+        table.insert(new_args, args[i])
+    end
+end
+if show_command then
+    print('modtools/create-unit ' .. table.concat(new_args, ' '))
+    return
+end
+dfhack.run_script('modtools/create-unit', table.unpack(new_args))