fix db opening error with absolute path on windows

[recursivecurry]

fix #282 (SQLITE_CANTOPEN error when cached.Database is called with absolute path on windows).

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Creating db using cached.Database with absolute path has error on windows.
below is my code and error message

code

var sqlite = require('sqlite3');
var current_db = new sqlite.cached.Database('current.db');    // OK
var relative_db = new sqlite.cached.Database('folder\\current.db');    // OK
var absolute_db = new sqlite.cached.Database('C:\\current.db');    // ERROR!!!

error message

events.js:72
        throw er; // Unhandled 'error' event
              ^
Error: SQLITE_CANTOPEN: unable to open database file

[recursivecurry]

No feedback? I add some comment to explain my fix.

Previous cached.Database code classify the path string by checking first character of path is '/'. However, Windows absolute path doesn't start with '/'. In Windows, absolute starts with drive character like 'C', 'D'. So I use node.js's path.resolve function which resolve the input path to an absolute path. I verified my code on windows 7(64bit) and ubuntu 12.04(64bit).

[springmeyer]

Sorry for the delay in commenting @everyevery - this fix looks great. I'll merge and test myself when I have a chance. Thanks!