Refactor page-generators into one page-generator
Reason?
The page generators were all doing the same thing
Move page generation into separate methods
Remove redundant generate in method names
Rename Generators
Use the correct syntax highlighter in README
Add Q!
Directory and file helpers
Filesystem helper

#Usage 

```javascript
var Fs = require('filesystem')
  , base;

base = new Fs('base path');

base.directory('dir')
.directory('anotherdir', function (anotherdir) {
	anotherdir.file('file', 'some content');
})
.file('files')
.done(callback)

```
PageGenerator

#Usage

## generate(options, next)

options: { name: 'name', type: 'md|html' }

```javascript
PageGenerator.page({name: 'index', type: 'html'},
function (content) {
  //content contains the contents of the page
});
```

#all(next)

Returns a hash with all the available pages

```javascript
PageGenerator.all(function (pages) {
  pages['index'];
});
```
Site generator