check mod_rewrite on install

[DevAlien]

When you install the cms the system will check if you have the mod_rewrite enabled.
The problem is that if apache is running under CGI/FCGI as is doing on my server we can't check with the apache functions.

Proposed solution:
While the installer is running we could do a ajax request to a page in a subfolder that should be loaded with the mod_rewrite. If the mod_rewrite is enabled we will see the page if not we will receive a 500 header error

We should create a directory "check" in the install directory and inside we will insert a .htaccess file with:

RewriteEngine On
RewriteRule ^check([^/]*).html$ check.php?check=$1 [L]

and a file called check.php with this Code:

In that way we can do an ajax call to the file /check/check1.html and if we get enabled it's working if we get the 500 error the mod_rewrite is not enabled