more abstractions for more complex tests
more tests
generic tests using gemstate
template for object_gemstate_...
use template for gemstate tests
use [pix_test] rather than [pix_image]

so we are not dependent on any plugins
provide a texture
create invisible window

so the tests are less annoying
multiple call args for pix_multitexture

it seems that there are different errors for [pix_multitexture 1] and [pix_multitexture 3]
more orders to test
don't print empty destroy message
added even more combinations to test
use CR-mode for reading objects
remove trailing semicolon
run test (for parallel)
prepare to use GNU parallel
make sure rendering is turned off *before* window destruction
send start/stop-rendering messages to [gemhead]s

Closes https://github.com/umlaeute/Gem/issues/44