Use faster compare methods

The static compare methods are significantly
faster than scala's Rich<Prim> compare methods,
and they are equivalent speed to subtraction but
handle edge cases correctly.

modules/common/src/main/model.scala

@@ -5,7 +5,7 @@ case class ApiVersion(value: Int) extends AnyVal with IntValue with Ordered[ApiV
   def v2 = value == 2
   def v3 = value == 3
   def v4 = value == 4
-  def compare(other: ApiVersion) = value compare other.value
+  def compare(other: ApiVersion) = Integer.compare(value, other.value)
   def gt(other: Int) = value > other
   def gte(other: Int) = value >= other
 }

modules/plan/src/main/model.scala

@@ -27,8 +27,8 @@ object Usd {
   def apply(value: Int): Usd = Usd(BigDecimal(value))
 }
 case class Cents(value: Int) extends AnyVal with Ordered[Cents] {
-  def compare(other: Cents) = value compare other.value
-  def usd = Usd(value / 100d)
+  def compare(other: Cents) = Integer.compare(value, other.value)
+  def usd = Usd(BigDecimal(value, 2))
   override def toString = usd.toString
 }
 

modules/socket/src/main/Socket.scala

@@ -14,7 +14,7 @@ object Socket extends Socket {
   case class Uids(uids: Set[Uid])
 
   case class SocketVersion(value: Int) extends AnyVal with IntValue with Ordered[SocketVersion] {
-    def compare(other: SocketVersion) = value compare other.value
+    def compare(other: SocketVersion) = Integer.compare(value, other.value)
     def inc = SocketVersion(value + 1)
   }
 

modules/study/src/main/Chapter.scala

@@ -151,7 +151,7 @@ object Chapter {
   case class IdName(id: Id, name: Name)
 
   case class Ply(value: Int) extends AnyVal with Ordered[Ply] {
-    def compare(that: Ply) = value - that.value
+    def compare(that: Ply) = Integer.compare(value, that.value)
   }
 
   def defaultName(order: Int) = Name(s"Chapter $order")

modules/tree/src/main/Eval.scala

@@ -56,7 +56,7 @@ object Eval {
     def invert = Cp(value = -value)
     def invertIf(cond: Boolean) = if (cond) invert else this
 
-    def compare(other: Cp) = value compare other.value
+    def compare(other: Cp) = Integer.compare(value, other.value)
 
     def signum: Int = Math.signum(value).toInt
   }
@@ -75,7 +75,7 @@ object Eval {
     def invert = Mate(value = -value)
     def invertIf(cond: Boolean) = if (cond) invert else this
 
-    def compare(other: Mate) = value compare other.value
+    def compare(other: Mate) = Integer.compare(value, other.value)
 
     def signum: Int = Math.signum(value).toInt