Fixed gamma calculation when x==1.

v0.9.4

Fix gamma calculation for x==1

Added the --brief option.

v0.9.3

Add tests

Bug fix release.

1. Fixed a precision problem that caused the SND z-value for 0.99 to be 2.577 instead of 2.576.
2. Increased the probabilities to z-tables precision to 3 from 2.

Initial release.

v0.9.0

Removed -d from example, it is not a valid option