improve tests makefile
give meaningful names to tests
fix reading regressors data from stdin

no buffering nor other annoyances
update expected tests results
fix and improve test on interaction tests
written (failing) test
fix cis-trans calling sql query
missing positions annotations are treated as 'trans'
genes and snps annotations are optional
simplify test on optional annotation
robustify and improve test on optional annotation
rm dangling debug statement
optionally print out table header
print out session info just before main loop
update expected results to latest R setup

results under lme4_1.1-7 are slightly different from previous ones
support simple model with no fixed nor random effects