handle missing input files
Merge pull request #484 from ged-lab/fix/assemstats3-nofile

handle missing input files for sandbox/assemstats3.py
tests runnable after installation
refinements for jenkins
astyle
enhanced Makefile + reports + more tests coverage

add target for python test coverage text report;
clarified where the HTML report is

Added additional tests

remove unused code as per https://github.com/ged-lab/khmer/issues/441#issuecomment-44744559
remove scripts that used CountingHash::max_hamming1_count
Document code & sandbox script removal
Changelog reordering
valgrind inspired cleanups
memleaks begone
more gifts from valgrind

Including a couple notable memory leaks!
split coverity target in two: -build and -upload. Added configuration target
match types