Revamping the FlatBuffers docs.

Adding an API reference for the supported languages.

General docs cleanup, including a new `tutorial` section that
supports all of the supported languages.

Added samples for each supported language to mirror the new
tutorial page.

Cleaned up all the links by making them `@ref` style links,
instead of referencing the names of the generated `.html` files.

Removed all generated files that were unnecessarily committed.

Also fixed the C# tests (two were failing due to a missing file).

Bug: b/25801305

Tested: Tested all samples on Ubuntu, Mac, and Android. Docs were
generated using doxygen and viewed on Chrome.

Change-Id: I2acaba6e332a15ae2deff5f26a4a25da7bd2c954

samples/csharp_sample.sh

@@ -0,0 +1,49 @@
+#!/bin/bash
+# Copyright 2015 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Note: This script runs on Mac and Linux. It requires `mono` to be installed
+# and `flatc` to be built (using `cmake` in the root directory).
+
+sampledir=$(cd $(dirname $BASH_SOURCE) && pwd)
+rootidr=$(cd $sampledir/.. && pwd)
+currentdir=$(pwd)
+
+if [[ "$sampledir" != "$currentdir" ]]; then
+  echo Error: This script must be run from inside the $sampledir directory.
+  echo You executed it from the $currentdir directory.
+  exit 1
+fi
+
+# Run `flatc`. Note: This requires you to compile using `cmake` from the
+# root `/flatbuffers` directory.
+if [ -e ../flatc ]; then
+  ../flatc --csharp --gen-mutable monster.fbs
+elif [ -e ../Debug/flatc ]; then
+  ../Debug/flatc --csharp --gen-mutable monster.fbs
+else
+  echo 'flatc' could not be found. Make sure to build FlatBuffers from the \
+       $rootdir directory.
+  exit 1
+fi
+
+echo Compiling and running the C# sample.
+
+# Compile and execute the sample.
+mcs SampleBinary.cs MyGame/Sample/*.cs ../net/FlatBuffers/*.cs
+mono SampleBinary.exe
+
+# Cleanup temporary files.
+rm SampleBinary.exe
+rm -rf MyGame/