Don't bother mentioning the IRIX 'inst' and 'tardist' package formats

Change-Id: I11c2f7fa72a1bc8a2c621ed928dc33a8410f1eee
Don't bother mentioning the Tru64 'setld' package format

Change-Id: I2a9707c70637fe5bae5d16fd45e9603318d5d82f
PackageMaker does not exist any more

Change-Id: Iefd1980fc87daa709e8e5c833407c2595e71b401