Added new method addInner() for adding content to already exiting inner
content of a html object.

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
Final integration of Admin app into Core app

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
WIP Theming

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
New composer support

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>