Fixes gh-551 Convert "Storing data w vinyl" article to ReST

Author: lenkis

conf.py

@@ -15,6 +15,7 @@
 
 extensions = [
     'sphinx.ext.todo',
+    'sphinx.ext.imgmath',
     'sphinx.ext.ifconfig',
     'sphinx.ext.intersphinx',
     'sphinx.ext.imgconverter',
@@ -48,7 +49,7 @@
     'doc/1.9/book/admin.rst',
     'doc/1.9/book/box/box_introspection.rst',
     'doc/1.9/book/cookbook.rst',
-    'doc/1.9/book/box/vinyl.rst',
+    'doc/1.9/book/box/engines/vinyl.rst',
     'doc/1.9/dev_guide/box_protocol.rst',
     'doc/1.9/dev_guide/internals.rst',
     'doc/1.9/reference/configuration/cfg_*',

doc/1.9/book/box/vinyl/i1.png renamed to doc/1.9/book/box/engines/i1.png

@@ -0,0 +1,31 @@
+.. _engines-chapter:
+
+********************************************************************************
+Storage engines
+********************************************************************************
+
+A storage engine is a set of very-low-level routines which actually store and
+retrieve tuple values. Tarantool offers a choice of two storage engines:
+
+* memtx (the in-memory storage engine) is the default and was the first to
+  arrive.
+
+* vinyl (the on-disk storage engine) is a working key-value engine and will
+  especially appeal to users who like to see data go directly to disk, so that
+  recovery time might be shorter and database size might be larger.
+
+  On the other hand, vinyl lacks some functions and options that are available
+  with memtx. Where that is the case, the relevant description in this manual
+  contains a note beginning with the words "Note re storage engine".
+
+Further in this section we discuss the details of storing data using
+the vinyl storage engine.
+
+To specify that the engine should be vinyl, add the clause ``engine = 'vinyl'``
+when creating a space, for example:
+
+.. code-block:: lua
+
+    space = box.schema.space.create('name', {engine='vinyl'})
+
+.. include:: vinyl.rst

doc/1.9/book/box/vinyl/i10.png renamed to doc/1.9/book/box/engines/i10.png

@@ -18,3 +18,4 @@ This chapter contains the following sections:
    authentication
    triggers
    limitations
+   engines/index