Add. formatter.mix Compatiable with lualogging
Extend file writer to support rolling file.
Add. max_size option in bytes.
Add. close_file if true then each time we open file, write message and close file. (default false).
Change. log date now is date when file was open.
Update rockspec
Fix. writer.file.roll
Add. rockspec for v0.1.0
Fix. Use ansicolors in writer.comsole.color
Add. lua-log-0.1.1-1.rockspec
Implement async servers(Lane/ZMQ/UDP)
Each async writer can use existed async server or create new one.
```lua
require "log.writer.async.server.lane".run("inproc://main.logger",
  "return require 'log.writer.file.by_day'.new('./logs', 'events1.log', 6000)"
)

require "log.writer.async.server.lane".run("inproc://main.logger",
  "return require 'log.writer.file.by_day'.new('./logs', 'events2.log', 6000)"
)

local LOG = require"log".new(
  require "log.writer.async.lane".new("inproc://main.logger")
)
```
Merge branch 'master' into lane