[FEATURE] added autoloading for plugins

a plugin has now a namespace, e.g.:

Phile\Plugin\PhileParserMarkdown

this namespace is used to autoload classes.

example:
Namespace: Phile\Plugin\PhileParserMarkdown\Parser\Markdown
File: plugins/phileParserMarkdown/Classes/Parser/Markdown.php

Releases: 0.9.3
[REFACTOR] moved markdown parser class from core into plugin
[REFACTOR] moved meta parser class from core into plugin
[REFACTOR] use autoloader for plugins
[REFACTOR] move twig class from core to plugin
Merge pull request #85 from PhileCMS/feature/AutoloadForPlugin

[FEATURE] autoload for plugins
[REFACTOR] rename init methods
[REFACTOR] change doc comment
[REFACTOR] change plugin structure

- moved all plugins into vendor directories
- rename namespace of all plugins
[REFACTOR] remove deprecated interfaces
update changelog
change format
change format
formatting for bold and nested lists
bold to italic - easier to read
Update Changelog.md
spelling
change version number
auto generated doc comments
Merge branch 'release/1.0.0' of github.com:PhileCMS/Phile into release/1.0.0