multiple improvements to logging

- added style.log table
- removed contextmenu
- use ctrl+click to copy individual log entries
- use icon instead of + or - for log items in logview

data/plugins/contextmenu.lua

@@ -42,24 +42,6 @@ keymap.add {
   ["menu"] = "context:show"
 }
 
-local function copy_log()
-  local item = core.active_view.hovered_item
-  if item then
-    system.set_clipboard(core.get_log(item))
-  end
-end
-
-local function open_as_doc()
-  local doc = core.open_doc("logs.txt")
-  core.root_view:open_doc(doc)
-  doc:insert(1, 1, core.get_log())
-end
-
-menu:register("core.logview", {
-  { text = "Copy entry", command = copy_log },
-  { text = "Open as file", command = open_as_doc }
-})
-
 if require("plugins.scale") then
   menu:register("core.docview", {
     { text = "Cut",         command = "doc:cut" },