Redid plugin system

- Plugin's are class-based
- Config is optional
- Added user guide
- Split events from Plugins (now called Plug, see laravel 3 Events for
docs)
- Redid the bundled edample plugin to reflect this change
- Added plugin manager
restructured some code

- Plugins::instance() instead of factory (we're not supporting multiple
instances)
- Plugin::install() and Plugin::init() should not be overwriteable (use
_init() and _install())
- More docblocks
- Updated bundled plugin to reflect the change
bug fixes and examplary plugin manager controller

(config based management tested and working)
forgot to add is_active to the DB manager
fixed up DB manager, made manager controller extendable
controller typo
updated guide to reflect changes
Plugin install task added
Update README.md

describe installation process, added authors
get correct path to config storage folder & DB table name for the installer task
Merge pull request #2 from Vheissu/develop

Merge Develop into Master