ARROW-266: [C++] Fix broken build due to Flatbuffers namespace change

Author: Wes McKinney <wesm@apache.org>

Closes #122 from wesm/ARROW-266 and squashes the following commits:

6193323 [Wes McKinney] Fix broken build due to Flatbuffers namespace change

Author: wesm

cpp/src/arrow/ipc/adapter.cc

@@ -41,7 +41,7 @@
 
 namespace arrow {
 
-namespace flatbuf = apache::arrow::flatbuf;
+namespace flatbuf = org::apache::arrow::flatbuf;
 
 namespace ipc {
 

cpp/src/arrow/ipc/metadata-internal.cc

@@ -37,7 +37,7 @@ typedef flatbuffers::Offset<void> Offset;
 
 namespace arrow {
 
-namespace flatbuf = apache::arrow::flatbuf;
+namespace flatbuf = org::apache::arrow::flatbuf;
 
 namespace ipc {
 

cpp/src/arrow/ipc/metadata-internal.h

@@ -28,7 +28,7 @@
 
 namespace arrow {
 
-namespace flatbuf = apache::arrow::flatbuf;
+namespace flatbuf = org::apache::arrow::flatbuf;
 
 class Buffer;
 struct Field;

cpp/src/arrow/ipc/metadata.cc

@@ -33,7 +33,7 @@
 
 namespace arrow {
 
-namespace flatbuf = apache::arrow::flatbuf;
+namespace flatbuf = org::apache::arrow::flatbuf;
 
 namespace ipc {