fix kmparticle(), close #7

+ accept void pointers in kmparticle()
+ return nonzero for NULL argument in kmparticle_ptr()
re-enable former segfaulting unittest
Merge branch 'fix-particles' into develop

* fix-particles:
  re-enable former segfaulting unittest
  fix kmparticle(), close #7
rewrite draw unittest

See #10
rewrite module unittest

See #10.
rewrite particle unittest

See #10.
rewrite sys unittest

See #10.
rewrite main test function

See #10.
remove old test framewok

See #10.
update makefiles

+ Add FindCheck CMake module
+ Add Check library dependency
+ Rename test-runner executable

See #10
Merge branch 'switch-unittests-to-check' into develop

Close #10

* switch-unittests-to-check:
  update makefiles
  remove old test framewok
  rewrite main test function
  rewrite sys unittest
  rewrite particle unittest
  rewrite module unittest
  rewrite draw unittest
Merge branch 'develop' into entity-system

Merge the feature required for further developing

* develop:
  update makefiles
  remove old test framewok
  rewrite main test function
  rewrite sys unittest
  rewrite particle unittest
  rewrite module unittest
  rewrite draw unittest
  re-enable former segfaulting unittest
  fix kmparticle(), close #7

Conflicts:
	test/main.c
	test/test.h
rewrite entity unittest

See #9.