fixed hrc unit test and added simple test case

implemented hrc serialization for empty skeletons

Tests/QGearsMain/misc/test_hrc_empty.hrc

@@ -0,0 +1,8 @@
+:HEADER_BLOCK 2
+:SKELETON test_empty_skeleton
+:BONES 0
+
+null
+root
+1.5
+1 model.1

Tests/QGearsMain/misc/test_hrc_simple.hrc

@@ -0,0 +1,18 @@
+:HEADER_BLOCK 2
+:SKELETON test_skeleton
+:BONES 3
+
+bone.1
+root
+1.5
+1 model.1
+
+bone.1.1
+bone.1
+2
+1 model.1.1
+
+bone.2
+root
+3.125
+3 model.2-1 model.2-2 model.2-3