add --autocenter option to make it easier to test 2d objects properly

Conflicts:
	src/Camera.cc
	tests/CMakeLists.txt
redo 2d tests to be viewed from the top down. experiment w altering viewall code

Conflicts:
	src/Camera.cc
	tests/CMakeLists.txt
	tests/regression/cgalpngtest/resize-2d-tests-expected.png
	tests/regression/cgalpngtest/rotate_extrude_dxf-tests-expected.png
	tests/regression/cgalpngtest/text-font-alignment-tests-expected.png
	tests/regression/cgalpngtest/text-font-direction-tests-expected.png
	tests/regression/cgalpngtest/text-font-simple-tests-expected.png
	tests/regression/cgalpngtest/text-font-tests-expected.png
	tests/regression/dumptest/resize-2d-tests-expected.csg
	tests/regression/opencsgtest/intersection2-tests-expected.png
	tests/regression/opencsgtest/resize-2d-tests-expected.png
	tests/regression/opencsgtest/rotate_extrude_dxf-tests-expected.png
	tests/regression/opencsgtest/text-font-alignment-tests-expected.png
	tests/regression/opencsgtest/text-font-direction-tests-expected.png
	tests/regression/opencsgtest/text-font-simple-tests-expected.png
	tests/regression/opencsgtest/text-font-tests-expected.png
	tests/regression/throwntogethertest/resize-2d-tests-expected.png
	tests/regression/throwntogethertest/rotate_extrude_dxf-tests-expected.png
	tests/regression/throwntogethertest/text-font-alignment-tests-expected.png
	tests/regression/throwntogethertest/text-font-direction-tests-expected.png
	tests/regression/throwntogethertest/text-font-simple-tests-expected.png
	tests/regression/throwntogethertest/text-font-tests-expected.png
Removed debug info
make default render like it was before. (bbox.center=center)
Fixed failing tests by adjusting some mistakes done while cherry-picking from the test_3d_export branch