[TASK] Update readme.md

Update link to archive of current version on SourceForge
Add reference to release notes of current version

Change-Id: Ib70021be9a24307e23fcf1a3e0ea11510afc0b31
[FIX] Fix some doxygen issues

- Fix typo in section definition
- Change filename tags of target-mutex.c files to be unambiguous

Change-Id: I4c9cdec3ebd7a56ca0e98c6e79965db8c145d2e3
[FIX] Fix ambiguous doxygen filename tags

Change filename tags of target-mutex.c files to be unambiguous.

Change-Id: Ic9f4831ec8d13c77aab710b5b44e5151669ff32e