added joins and groupby support

Example:
'fieldname' => array
(
	'label'                   =>
&$GLOBALS['TL_LANG']['tl_tablename']['fieldname'],
	'exclude'                 => true,
	'inputType'               => 'tableLookup',
	'eval'                    => array
	(
		'doNotCopy'           => true,
		'tl_class'            => 'clr',
		'foreignTable'        => 'tl_foreign_tablename',
		'fieldType'           => 'checkbox',
		'listFields'          => array('field1', 'field2'),
		'searchFields'        => array('field1', 'jtf.content'),
		'joins'               => array
		(
			'jtf' => array
			(
				'table' => 'tl_translation_fields',
				'jkey' => 'fid',
				'fkey' => 'title'
			)
		),
		'sqlGroupBy'          => 'jtf.fid',
		'matchAllKeywords'    => true
	),
	'sql'                     => "blob NULL"
)
added list_value_callback

Example:
'fieldname' => array
(
	'label'                   =>
&$GLOBALS['TL_LANG']['tl_tablename']['fieldname'],
	'exclude'                 => true,
	'inputType'               => 'tableLookup',
	'eval'                    => array
	(
		'doNotCopy'           => true,
		'tl_class'            => 'clr',
		'foreignTable'        => 'tl_foreign_tablename',
		'fieldType'           => 'checkbox',
		'listFields'          => array('field1', 'field2'),
		'searchFields'        => array('field1', 'jtf.content'),
		'joins'               => array
		(
			'jtf' => array
			(
				'table' => 'tl_translation_fields',
				'jkey' => 'fid',
				'fkey' => 'title'
			)
		),
		'sqlGroupBy'          => 'jtf.fid',
		'matchAllKeywords'    => true
	),
	'list_value_callback' => function ($varValue, $strField)
	{
		return \TranslationFields::translateValue($varValue);
	},
	'sql'                     => "blob NULL"
)
added changes to changelog
optimized coding style to PSR-2
added README.md
Improved changelog
Refactored so we have more methods that can be overridden with ease
Speeding up comparisons a little
Updated README a little
CS
CS
Make sure columns are correctly aliased when using JOIN tables
CS
Allow different types of joins
Using importStatic
Using haste now for formatting labels
More formatting that we can leave to haste
Made joining more explicit without aliasing
Complete rewrite of the widget
List value callback probably has to be readded but for now it doesn’t exist anymore