Org reader: add basic file inclusion mechanism

Support for the `#+INCLUDE:` file inclusion mechanism was added.
Recognized include types are *example*, *export*, *src*, and normal org
file inclusion.  Advanced features like line numbers and level selection
are not implemented yet.

Closes: #3510

4 files changed, 27 insertions, 0 deletions

diff --git a/test/command/3510-export.latex b/test/command/3510-export.latex
new file mode 100644
index 000000000..6d8636322
--- /dev/null
+++ b/test/command/3510-export.latex
@@ -0,0 +1 @@
+\emph{Hello}
\ No newline at end of file
diff --git a/test/command/3510-src.hs b/test/command/3510-src.hs
new file mode 100644
index 000000000..ad5744b80
--- /dev/null
+++ b/test/command/3510-src.hs
@@ -0,0 +1 @@
+putStrLn outString
diff --git a/test/command/3510-subdoc.org b/test/command/3510-subdoc.org
new file mode 100644
index 000000000..5bcc6678a
--- /dev/null
+++ b/test/command/3510-subdoc.org
@@ -0,0 +1,5 @@
+* Subsection
+
+Included text
+
+Lorem ipsum.
diff --git a/test/command/3510.md b/test/command/3510.md
new file mode 100644
index 000000000..7993db848
--- /dev/null
+++ b/test/command/3510.md
@@ -0,0 +1,20 @@
+See <http://orgmode.org/manual/Include-files.html>
+```
+% pandoc -f org -t native
+Text
+
+#+include: "command/3510-subdoc.org"
+
+#+INCLUDE: "command/3510-src.hs" src haskell
+#+INCLUDE: "command/3510-export.latex" export latex
+
+More text
+^D
+[Para [Str "Text"]
+,Header 1 ("subsection",[],[]) [Str "Subsection"]
+,Para [Str "Included",Space,Str "text"]
+,Plain [Str "Lorem",Space,Str "ipsum."]
+,CodeBlock ("",["haskell"],[]) "putStrLn outString\n"
+,RawBlock (Format "latex") "\\emph{Hello}"
+,Para [Str "More",Space,Str "text"]]
+```