Tweak error messages.
Now, the "homepage" property should be read properly.
Improve README.md.
Clean up package.json.

* bin/grunt-sitemap isn't really useful so remove it
* only install the needed files
* bump grunt dependency
Fix issue when building on Windows.
Only remove `root` when needed.
Merge pull request #18 from XhmikosR/issue8

Only remove `root` when needed.
Merge pull request #16 from XhmikosR/readme

Improve README.md.
Merge pull request #14 from XhmikosR/pkg.homepage

Now, the "homepage" property should be read properly.
Merge pull request #12 from XhmikosR/errMsg

Tweak error messages.
Merge pull request #10 from XhmikosR/package.json

Clean up package.json.
Merge pull request #17 from XhmikosR/cakefile

Fix issue when building on Windows.
Add more xmlns headers to generated XML
Fix issues when the `siteRoot` and and `URL` don't have slashes.
Handle the `siteRoot: './'` case too.