KAA-219: modularize logger, get rid of static variables, update init sequence to store logger in the Kaa context, rename KAA_NOT_VOID macro into KAA_RETURN_IF_NULL
KAA-229: further simplify logger and clean up redundant documentation. Remove unused macro in kaa_common.h
KAA-229: fix memory corruption when the log message is too large for the buffer.
KAA-229: make logger buffer size a constructor parameter
KAA-229: improve doxygen markdown
Merge branch 'c_sdk_refactoring' into feature/KAA-229

Conflicts:
	client/client-multi/client-c/test/test_kaa_bootstrap.c
	client/client-multi/client-c/test/test_kaa_common.c
	client/client-multi/client-c/test/test_kaa_context.c
	client/client-multi/client-c/test/test_kaa_event.c
	client/client-multi/client-c/test/test_kaa_log.c
	client/client-multi/client-c/test/test_kaa_profile.c
	client/client-multi/client-c/test/test_kaa_status.c
KAA-229: fix test build failure after merge
Merge pull request #35 from kaaproject/feature/KAA-229

KAA-229: Improve C EP SDK modularization (C logger)