Merge pull request #33 from hadleyrich/master

Fix up clock_rtc and add rtc.o to Makefile
License for libkakapo is now LGPL.
Use negative return values via int like everywhere else.
Closes #35
Add ENOTREADY return code, use in clock.c for osc running checks.
Closes #34
Add codeblocks project files to gitignore
Silence warnings