initial github markdown adapter

initial github markdown adapter
remove caching stuff
cs fixes
add github markdown api to readme
test existence of servicemanager factories
initial caching: add cache listener
add cache directory for tests to repository
typo / layout in readme
typo / layout in readme
adding tests for CacheListener
adding a service to use the cache
switch view helper to use the service
using push to add value within service tests
disable cache by default
add cache config hints to config
add hint for cache to readme
making gfm the default rendering method
remove github adapter from invokables array
start for v1.1.x
Merge branch 'feature/caching' into 1.1.x
Merge branch 'feature/github-markdown-adapter' into 1.1.x

Conflicts:
	config/maglmarkdown.local.php
	config/module.config.php
	src/MaglMarkdown/Module.php