Initial commit for the official OP-TEE documentation

This initial commit brings in all existing documentation found across
various gits making up the documentation for the OP-TEE project. So in
summary what this includes and what has been done is:

- Import all old documentation (optee_os, optee_client, optee_test and
  so on).
- Convert everything from markdown (*.md) to reStructuredText (*.rst).
- Add a couple of new pages (optee_docs, disclosure policy to name a
  few).
- Add Sphinx configuration.
- Add Travis configuration to enable automatic testing of future
  documentation patches.
- Finally, a general clean-up and verification of content,
  links as well as verification of build instructions etc has also been
  done.
diff --git a/building/linux/tee_framework.rst b/building/linux/tee_framework.rst
new file mode 100644
index 0000000..05a85b2
--- /dev/null
+++ b/building/linux/tee_framework.rst
@@ -0,0 +1,48 @@
+.. _linux_kernel:
+
+##########################
+Linux kernel TEE framework
+##########################
+
+.. todo::
+
+    Joakim: Jens to fill in information in the following sections. Eventually
+    this should be split up as two files, one under "Build and Run" and one
+    under "Architecture documentation".
+
+    History
+    - Refer to the patch when it was merged.
+    - Mention old and deprecated optee_linux driver.
+
+    Maintainer
+    - Jens and ... ?
+
+    Maillists
+    - Mention the get_maintainer script in kernel. 
+    - Tee-dev? (:ref:`contact`).
+
+    Build instructions
+    - How to enable it in kernel
+
+    KConfig flags
+    - What flags to enable to run OP-TEE.
+    - Reference to :ref:`optee_benchmark`.
+
+    Device Tree
+    - What nodes/thing are important for OP-TEE.
+    - Are OP-TEE DT things upstream? If not, why?
+
+    TEE kernel Internal Client API
+    - What is it?
+    - How can I use it?
+    - Is it upstream? If not, why?
+
+    Differences between kernel.org and linaro-swg/linux
+    - Why do we have a separate fork?
+    - Features being developed.
+    - Not meant to go upstream.
+    - Should people send patches to the mailinglist or create PRs at
+    linaro-swg/linux?
+
+    External references
+    - (Links to) Documentation in the official kernel?