Add linalg.add_dot
Fix makefile
Merge pull request #69 from untom/fix_Makefile

Fix Makefile to properly install in /usr/local/... when run as root.
Merge pull request #68 from untom/linald_add_diag

Add linalg.add_dot.
Change default overwrite param value of add_diag; update linalg ref docs.
Update CHANGES.