core: add theme support

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
core: align c datastructure at ini file layout

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
core: adjust to new project/conf file format

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
core: refactor project structure

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>