Replace anonymous fifo with POSIX pipe
Initial multi-shell wvtest harness
Try harder to determine current SHELL
Run tests against BASH first

test harness displays fullest diagnostic info under BASH, so test with
that shell first, to maximize the chance that test errors are helpful.
Passing tests
Teach wvtestrun about multiple shells
Refactor test harness

Make file under test an explicit ENV var
Refactor harness functions appropriately
Fix Makefile target
Fix whitespace
Refactor _max_letterpress_width
Preserve exit status after test run
bump
Replace bc dependency with awk
Add Travis badge for testing branch
Update README
Add multi-shell prereqs to Travis build
Simplify sourcing for test runs
Extract function
Clean up test script
Eliminate hard-coded composure dir