Implement naive linear relaxation bounding
Merge branch 'master' into bound

Conflicts:
	knapsack/Knapsack.java
Do not recalculate weight and value for bound at each node
In bound calculation, keep weight under constraint

Don't add a fraction of an item's value if adding that fraction of its
weight puts the knapsack over the capacity
Test decision vector no longer used by bound method
Now that bound doesn't recalc weight, add assertion for clarity
Replace recursive branch algorithm with stack-and-loop branch algorithm

Recursion hit a stack overflow somewhere between 1000 and 10000 items
Rearrange code to make it easier to read