Some new stuff

Here is some new stuff I hacked together during the last week. Open for review ;)

## Access control
Acces control is limited and very specific:

* Only **Projects** are tracked.
* There are only 4 "hard wired" **Actions**:<br />`view`, `create`, `edit` and `manage`.
* It is based on **groups** a user automatically belongs to or can be assigned to.<br />
For every project two **system groups** are created by default:<br />`Public` and `User`.

The special **admin user** role that is assigned using the `config.json` file is granted global access.

Following is an example setup for a security tracker with non public access and two additionally created custom groups:
![Access groups](https://f.cloud.github.com/assets/33978/550822/fc7c42a0-c31a-11e2-82c8-85f4ea05b92e.png)

However, this is a very first step... lots of optimization and testing required here.

## Pagination

I searched the web for "PHP pagination MySQL" or similar, and this came up on the first page:
http://www.awcore.com/dev/1/3/Create-Awesome-PHPMYSQL-Pagination_en

I liked the way the author solved "the problem", the code looked acceptable,... so I "forked" and Joomla!"d it :)
The CSS was somewhat conflicting (for me), so I took one of the beautiful styles from the author, and now it looks like this:

![Pagination](https://f.cloud.github.com/assets/33978/550842/960024f0-c31b-11e2-971c-c7d870320600.png)

For now it only generates "plain links" adding a `&page=n` parameter to the current URL.
When we implement the search functionality, this must be revised.
I can also imagine a JavaScript (AJAX) based solution using this.

**Note**: The license on this is very unclear. Seems that is provided as a "snippet". Maybe our legal department should have a look at this ;)

## Database updates
Obsolete tables and table fields have been removed while others have been added ;)

**Full reinstall required !**

## Avatar support

On the first log in, the application tries to fetch the users avatar and store it locally.

This requires cURL.

## Debugging and Logging

Added a TrackerDebugger class that... handles debugging :P
Added a CallbackLogger class to provide database query logging.
A log file can be written to log queries even during redirects ;)
Exception rendering has been improved to include clickable file links using the xdebug protocol.

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Happy testing
=;)