Add gitignore file
Add. MSVC project files
Add. uv.loop function.
Change. uv.close(true) close all handles before trying close loop object.

```Lua
local uv = require "lluv"
local loop = uv.loop()

local timer = uv.timer(loop)
local timer = uv.timer(loop)

print(loop:close())     -- EBUSY
print(loop:close(true)) -- Pass
```
Fix. fbuf object does not GC'ed.