Fix of bug #97

-- Fixed GROUP:IsAlive()
--- Returns if the Group is alive.
-- The Group must:
--
--   * Exist at run-time.
--   * Has at least one unit.
--
-- When the first @{Unit} of the Group is active, it will return true.
-- If the first @{Unit} of the Group is inactive, it will return false.
--
-- @param #GROUP self
-- @return #boolean true if the Group is alive and active.
-- @return #boolean false if the Group is alive but inactive.
-- @return #nil if the group does not exist anymore.

-- Fixed Identifiable:IsAlive()
--- Returns if the Identifiable is alive.
-- If the Identifiable is not alive, nil is returned.
-- If the Identifiable is alive, true is returned.
-- @param #IDENTIFIABLE self
-- @return #boolean true if Identifiable is alive.
-- @return #nil if the Identifiable is not existing or is not alive.

-- Fixed UNIT:IsAlive()
--- Returns if the Unit is alive.
-- If the Unit is not alive, nil is returned.
-- If the Unit is alive and active, true is returned.
-- If the Unit is alive but not active, false is returned.
-- @param #UNIT self
-- @return #boolean true if Unit is alive and active.
-- @return #boolean false if Unit is alive but not active.
-- @return #nil if the Unit is not existing or is not alive.

-- Updated all test missions, as this is a core change.

docs/Documentation/Identifiable.html

@@ -474,6 +474,10 @@ The DCS Identifiable is not existing or alive.  </p>
 	
 <p>Returns if the Identifiable is alive.</p>
 
+	
+<p>If the Identifiable is not alive, nil is returned. <br/>
+If the Identifiable is alive, true is returned.  </p>
+
 		<h3>Return values</h3>
 			<ol>
 				<li>
@@ -485,7 +489,7 @@ true if Identifiable is alive.</p>
 				<li>
 				
 <p><em>#nil:</em>
-The DCS Identifiable is not existing or alive.  </p>
+if the Identifiable is not existing or is not alive.  </p>
 
 				</li>
 			</ol>