Merge pull request #23 from opentable/SM/performance

Sm/performance
aError -> anError
Merge pull request #24 from youknowone/master

aError -> anError
Fix import

Change import #import "math.h" to #import <math.h> in NBPhoneNumberUtil.m.
This will prevent importing wrong header if you already have in the project a different header named math.h
Merge pull request #25 from alexterente/master

Fix import
fix a static analyzer error (value stored to var is never read)