Remove Value.Get() interfaces

These were only defined for a couple for flag types (ip, ipmask, uint16,
uint32) and weren't used anywhere. If you already knew the type well
enough to know that it was one of the few with a Get() interface, you
could cast yourself out of the Value...

ip.go

diff --git a/ip.go b/ip.go
index 9d53bd3..efa75fb 100644
--- a/ip.go
+++ b/ip.go
@@ -22,9 +22,6 @@
 	*i = ipValue(ip)
 	return nil
 }
-func (i *ipValue) Get() interface{} {
-	return net.IP(*i)
-}
 
 func (i *ipValue) Type() string {
 	return "ip"

ipmask.go

diff --git a/ipmask.go b/ipmask.go
index 6f85be9..09b9533 100644
--- a/ipmask.go
+++ b/ipmask.go
@@ -22,9 +22,6 @@
 	*i = ipMaskValue(ip)
 	return nil
 }
-func (i *ipMaskValue) Get() interface{} {
-	return net.IPMask(*i)
-}
 
 func (i *ipMaskValue) Type() string {
 	return "ipMask"

uint16.go

diff --git a/uint16.go b/uint16.go
index ec14ab0..ab1c1f9 100644
--- a/uint16.go
+++ b/uint16.go
@@ -19,10 +19,6 @@
 	return err
 }
 
-func (i *uint16Value) Get() interface{} {
-	return uint16(*i)
-}
-
 func (i *uint16Value) Type() string {
 	return "uint16"
 }

uint32.go

diff --git a/uint32.go b/uint32.go
index 05bc3bd..db635ae 100644
--- a/uint32.go
+++ b/uint32.go
@@ -18,9 +18,6 @@
 	*i = uint32Value(v)
 	return err
 }
-func (i *uint32Value) Get() interface{} {
-	return uint32(*i)
-}
 
 func (i *uint32Value) Type() string {
 	return "uint32"