change default FreshnessPeriod to 0 ms

set InterestLifetime to default value when not present

do not encode ChildSelector if at default value

refs #3944

Change-Id: I4a3ebf5512d0d2270798ed212eab7903ba8b8ed0
diff --git a/src/interest.hpp b/src/interest.hpp
index 8d3f29b..e98747e 100644
--- a/src/interest.hpp
+++ b/src/interest.hpp
@@ -242,13 +242,12 @@
     return m_interestLifetime;
   }
 
+  /**
+   * @brief Set Interest's lifetime
+   * @throw std::invalid_argument specified lifetime is < 0
+   */
   Interest&
-  setInterestLifetime(const time::milliseconds& interestLifetime)
-  {
-    m_interestLifetime = interestLifetime;
-    m_wire.reset();
-    return *this;
-  }
+  setInterestLifetime(time::milliseconds interestLifetime);
 
   /** @brief Check if Nonce set
    */