Implement OBSERVE

Change-Id: I63e3d5edeed3874697b5d4a230e5542ae515a1d7
View-query and pagination interface.

.gitignore:
  Added *.swp and .vimsession for vim.

binding.gyp:
  - I have left my custom libcouchbase installation directory. The idea is
    to have default directory in the *.gyp file and provide a comment, either
    in the top or nearby, explaining the meaning of `couchbase_root`
  - `-rpath=...` throws error, changed to `-rpath ...`

lib/couchbase.js:
  - Importing query.js module.
  - _init() callback to query module.
  - view() API does not take a callback and returns a Query() instance. We
    expect users to do,
        var q = cb.view("designdoc", "myview", queryparams)
        q.query(callback);

lib/http.js:
  - moved parameter validation under view() API to query.js, since we need to
    validate query parameters at several places.
  - view() API just returns the Query() instance.

lib/query.js:
  - implements the following query API.
      q.query(queryparams, callback)
      q.clone(queryparams)
      q.firspage(queryparams, callback)

  - implements the following paginator API.
      q.isNext()
      q.next(callback)
      q.prev(callback)

Added test cases for query in 08-query.js
Added test cases for pagination in 08-page.js
Updated test cases for 08-view.js