Fix RandomDoubleHP(), expand test program with floating point

Fix bug in RandomDoubleHP() that caused the function not to return;
expand test program with float/double random value tests; improve
Makefile with respect to test-program.

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>
Bump version to v0.1.2

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>