update to version 7
tests: restore & robustify floating point tests #6
tests: reenable pcalc.011 test using regex output
tests: accept 0 or 1 when truncating log(10) * log10(E)
tests: add regex output matching
tests: rename PCALC_SIMPLE_AT_CHECK helper
tests: use POSIX -E with sed
rework long double -> unsigned long long conversion #16