encoding: Improving structure and documentation of block helpers

This commit add several new helpers to simplify operations with
std::string:

- prependStringBlock
- makeStringBlock
- readString

The following functions are deprecated and their replacements:

- nonNegativeIntegerBlock (use makeNonNegativeIntegerBlock)
- prependBooleanBlock (use prependEmptyBlock)
- booleanBlock (use makeEmptyBlock)
- dataBlock (use makeBinaryBlock)
- nestedBlock (use makeNestedBlock)

Change-Id: Ic595ae64fc9c80c2c04e5fde1d8812e8b9debd60
Refs: #2951
diff --git a/src/name-component.hpp b/src/name-component.hpp
index c811c9b..6338477 100644
--- a/src/name-component.hpp
+++ b/src/name-component.hpp
@@ -150,7 +150,7 @@
    */
   template<encoding::Tag TAG>
   size_t
-  wireEncode(EncodingImpl<TAG>& block) const;
+  wireEncode(EncodingImpl<TAG>& encoder) const;
 
   /**
    * @brief Encode to a wire format
@@ -619,7 +619,7 @@
 template<class Iterator>
 inline
 Component::Component(Iterator first, Iterator last)
-  : Block(dataBlock(tlv::NameComponent, first, last))
+  : Block(makeBinaryBlock(tlv::NameComponent, first, last))
 {
 }