Docs: Support out-of-source reference-API builds

This was originally supported, however relative links to examples & templates made it fail.
Now files in the source tree are copied to the build-dir, with ".." replaced with "__"
to avoid having to mirror Blender's source-layout in the Sphinx build-dir.

Also skip uploading the built docs when an SSH user-name isn't passed to sphinx_doc_gen.sh
instead of aborting (so people w/o SSH access to our servers can use the shell-script).

doc/python_api/rst/bge.constraints.rst

@@ -8,11 +8,11 @@ Physics Constraints (bge.constraints)
 Examples
 --------
 
-.. include:: ../examples/bge.constraints.py
+.. include:: __/examples/bge.constraints.py
    :start-line: 1
    :end-line: 4
 
-.. literalinclude:: ../examples/bge.constraints.py
+.. literalinclude:: __/examples/bge.constraints.py
    :lines: 6-
 
 

doc/python_api/rst/bge.texture.rst

@@ -39,26 +39,26 @@ When the texture object is deleted, the new texture is deleted and the old textu
 
 .. module:: bge.texture
 
-.. include:: ../examples/bge.texture.py
+.. include:: __/examples/bge.texture.py
    :start-line: 1
    :end-line: 5
 
-.. literalinclude:: ../examples/bge.texture.py
+.. literalinclude:: __/examples/bge.texture.py
    :lines: 7-
 
-.. include:: ../examples/bge.texture.1.py
+.. include:: __/examples/bge.texture.1.py
    :start-line: 1
    :end-line: 6
 
-.. literalinclude:: ../examples/bge.texture.1.py
+.. literalinclude:: __/examples/bge.texture.1.py
    :lines: 8-
 
 
-.. include:: ../examples/bge.texture.2.py
+.. include:: __/examples/bge.texture.2.py
    :start-line: 1
    :end-line: 6
 
-.. literalinclude:: ../examples/bge.texture.2.py
+.. literalinclude:: __/examples/bge.texture.2.py
    :lines: 8-
 
 

doc/python_api/rst/include__bmesh.rst

@@ -41,7 +41,7 @@ For an overview of BMesh data types and how they reference each other see:
 Example Script
 --------------
 
-.. literalinclude:: ../../../release/scripts/templates_py/bmesh_simple.py
+.. literalinclude:: __/__/__/release/scripts/templates_py/bmesh_simple.py
 
 
 Stand-Alone Module

doc/python_api/rst/info_quickstart.rst

@@ -305,7 +305,7 @@ In Python, this is done by defining a class, which is a subclass of an existing
 Example Operator
 ----------------
 
-.. literalinclude:: ../../../release/scripts/templates_py/operator_simple.py
+.. literalinclude:: __/__/__/release/scripts/templates_py/operator_simple.py
 
 Once this script runs, ``SimpleOperator`` is registered with Blender
 and can be called from the operator search popup or added to the toolbar.
@@ -336,7 +336,7 @@ Example Panel
 Panels register themselves as a class, like an operator.
 Notice the extra ``bl_`` variables used to set the context they display in.
 
-.. literalinclude:: ../../../release/scripts/templates_py/ui_panel_simple.py
+.. literalinclude:: __/__/__/release/scripts/templates_py/ui_panel_simple.py
 
 To run the script: