Add initialisation of shared memory
Merge pull request #116 from neithernut/add-shm-initialisation

Add initialisation of shared memory
Add test files
Add cmake module for finding check framework
Add CMakeLists.txt files for test build-env
Ignore .test files
Enable adding sources and libraries to tests
Add objects/set.{c,h} files and CMakeLists.txt entry
Add initial interface definition
Add stubs for ws_set type implementation
Add implementation for ws_set_init()
Add implementation for ws_set_new()
Add implementation for ws_set_insert()
Add implementation for ws_set_union()
Add implementation for ws_set_insertsection()
Add implementation for ws_set_xor()
Add implementation for ws_set_is_subset()
Add implementation for ws_set_equal()
Add implementation for ws_set_cardinality()
Add implementation for ws_set_select()