Thanks to thorsten!

This introduces the setting single_instance_per_file and
the command line flag --single-instance.

Katarakt now exposes a dbus-API that allows TeX-editors to synchronize
the positions in source code and pdf via synctex.

TODO: The API allows to specify positions in the PDF as (page,x,y)
triple, but the x,y coordinates are currently ignored or set to 0,
respectively. We need more katarakt-internal API for this to be
implementable.

Thanks to Thorsten for finding a solution

The config option controls whether katarakt should quit if the given
file fails to open.  The command line switch toggles this behaviour.

The command line options right before each file will be used
individually.

If given file is not a local file it is handled as URL and stored to
temporary directory.

I use QSettings in ini format. See the qt documentation to learn about
file locations. If there is no config found the default values are used.

Also, fixed memory leaks.

Currently supported options are:
	- page NUM
	- fullscreen
	- help

make Viewer the central class
some minor changes (includes, const, ...)

remove some TODOs

move pdf drawing to the canvas class

resource manager now scales available images