Switch from boost pointers to std C++11 pointers

Most of this code is automated code changes:

```
set -e
SUB="s/dummy/dummy/"
for i in shared_ptr make_shared dynamic_pointer_cast weak_ptr enable_shared_from_this get_deleter; do
  SUB="$SUB;s/boost::$i/std::$i/g"
done
SUB="$SUB;s^#include <boost/shared_ptr.hpp>^#include <memory>^g"
SUB="$SUB;s^namespace boost^namespace std^g"

find . \( -name "*.cc" -o -name "*.h" -o -name "*.i" -o -name "*.cxx" -o -name "*.py" \) -print0 | xargs -0 sed -i "$SUB"
```

Only one manual change. In `./gr-fec/lib/fec_mtrx_impl.cc`, add
`#include <algorithm>`.

Author: ThomasHabets

docs/doxygen/other/shared_ptr_docstub.h

@@ -1,4 +1,4 @@
-namespace boost {
+namespace std {
 /*!
  * \brief shared_ptr documentation stub
  *
@@ -20,4 +20,4 @@ class shared_ptr
 }; // shared_ptr
 
 
-} // namespace boost
+} // namespace std

gnuradio-runtime/include/gnuradio/basic_block.h

@@ -17,7 +17,6 @@
 #include <gnuradio/runtime_types.h>
 #include <gnuradio/sptr_magic.h>
 #include <gnuradio/thread/thread.h>
-#include <boost/enable_shared_from_this.hpp>
 #include <boost/function.hpp>
 #include <boost/thread/condition_variable.hpp>
 #include <deque>
@@ -41,7 +40,7 @@ namespace gr {
  * processing functions.
  */
 class GR_RUNTIME_API basic_block : public msg_accepter,
-                                   public boost::enable_shared_from_this<basic_block>
+                                   public std::enable_shared_from_this<basic_block>
 {
     typedef boost::function<void(pmt::pmt_t)> msg_handler_t;
 
@@ -53,7 +52,7 @@ class GR_RUNTIME_API basic_block : public msg_accepter,
     typedef std::map<pmt::pmt_t, msg_queue_t, pmt::comparator> msg_queue_map_t;
     typedef std::map<pmt::pmt_t, msg_queue_t, pmt::comparator>::iterator
         msg_queue_map_itr;
-    std::map<pmt::pmt_t, boost::shared_ptr<boost::condition_variable>, pmt::comparator>
+    std::map<pmt::pmt_t, std::shared_ptr<boost::condition_variable>, pmt::comparator>
         msg_queue_ready;
 
     gr::thread::mutex mutex; //< protects all vars
@@ -291,7 +290,7 @@ class GR_RUNTIME_API basic_block : public msg_accepter,
      * store them. Each block has a vector to do this, and these never
      * need to be accessed again once they are registered with the RPC
      * backend. This function takes a
-     * boost::shared_sptr<rpcbasic_base> so that when the block is
+     * std::shared_sptr<rpcbasic_base> so that when the block is
      * deleted, all RPC registered variables are cleaned up.
      *
      * \param s an rpcbasic_sptr of the new RPC variable register to store.