update for render module [0.5.0]

This version introduces multiple enhancements:

use cache for storage joined templates and full rendered content
changed view and grid to abstract class
added handling of skins

Details of additions/deletions below:
--------------------------------------------------------------

Modified:   /Lib/loader.php
            -- Updated --
                _setPaths, define base skin directory

Modified:   /Lib/Core/Render/View/Grid/Abstract.php
            -- Updated --
                changed class to abstract class

Modified:   /Lib/Core/Render/View/Abstract.php
            -- Added --
                CORE_SKIN_DIRECTORY
                SKIN_DEFAULT
                CACHE_SUFFIX
                CACHE_DATA_SUFFIX
                $_cacheName to store class name for cache file creation
                getCacheName to return cache name
                _setCacheName to set cache name
                _prepareTemplateUrl, to check what template file is available, and return path to it
            -- Updated --
                $_options, added nwe options (module, cache, cache_data)
                __construct, added _setCacheName handling
                _createMainLayout, added cache handling
                _checkTemplatePath renamed to _getTemplateContent, removed checking that template exists
                _external, some logic changes
                render, added cache handling
                _joinTemplates temporary commented
                _templateCache to check that content is cached, and return it or cache it
            -- Removed --
                getSkinTemplate

Modified:   /Lib/config.ini
            -- Modified --
                changed version from 0.15.4 to 0.16.0

Modified:   /Lib/Core/Render/etc/config.ini
            -- Modified --
                changed version from 0.4.0 to 0.5.0