Refactor log makefiles and source directories

Ref #9 (closed) and #2

• Merge log/src Makefile and log/src/ana Makefile in one unique Makefile in log directory instead.
• ana and log headers are now in an unique include folder with ana in its own subfolder.
• and and log source files are still in the same organization.
• The produced objects files and executables are now in a log/target directory separated from source code.