In bug 729952, we identified that our current string hash function is quite poor. That bug contains an alternative hash function which performs much better. This bug is about making sure that all relevant code uses this improved hash function, and centralizing the code which computes hashes, so it's easier to change our hash function in the future, if need be.
Part of this bug will involve removing the hash function calls from nsCRT.
Didn't notice that bz already had a bug on this.