Added helper functions for nodes
Added some helper funtions for caching
LenNodes now takes a bool parameter, and includes cached nodes if true
Added unit testing for database functions (Fixes #5)
Changed Node to use net.IP instead of net.Addr
LenNodes now returns -1 on error
Fixed situations where improper error handling would cause Bad Things(TM) to happen
Fixed handling of net.IP type in database functions
Fixed an SQL syntax error
Improved error reporting in some database functions
Modified unit test in nodeatlas.go
Unsuccessfully tried to fix conversion issues in GetNode