org: fix broken links

* doc/org/upgrade2.org, doc/org/ioltl.org, doc/org/concepts.org: Here.
* doc/org/tut51.org: Fix example output.

doc/org/concepts.org

@@ -836,7 +836,7 @@ $txt
    :CUSTOM_ID: hoa
    :END:
 
-The [[http://adl.github.io/hoaf/][HOA format]] inherits several features from the [[:dstar][DSTAR format]], but
+The [[http://adl.github.io/hoaf/][HOA format]] inherits several features from the [[#dstar][DSTAR format]], but
 extends it in many ways, including support for non-deterministic
 automata, alternating automata, and for arbitrary acceptance conditions.
 
@@ -1107,7 +1107,7 @@ correspond to any =twa= flag.
    :CUSTOM_ID: named-properties
    :END:
 
-In addition to [[#proeprty-flags][property flags]], automata in Spot can be tied to an
+In addition to [[#property-flags][property flags]], automata in Spot can be tied to an
 arbitrary number of objects via a system of named properties that is
 implemented mostly as an =std::map= between =std::string= and =void*=.
 

doc/org/ioltl.org

@@ -44,7 +44,7 @@ Spot's default LTL parser is able to parse the syntaxes of many tools,
 such as [[http://spinroot.com][Spin]], [[http://vlsi.colorado.edu/~rbloem/wring.html][Wring]], [[http://goal.im.ntu.edu.tw][Goal]], etc.  For instance here are the preferred ways
 to express the same formula for different tools.
 
-# <<tab:formula-syntaxes>>
+#+NAME: tab:formula-syntaxes
 | Tool         | Formula                 |
 |--------------+-------------------------|
 | Spot         | =G(a -> (b R !c))=      |

doc/org/tut51.org

@@ -393,7 +393,7 @@ this reason.
 #+END_SRC
 
 #+RESULTS:
- q[[file:kripke-1.svg]]
+[[file:kripke-1.svg]]
 
 * Checking a property on this state space
 

doc/org/upgrade2.org

@@ -85,7 +85,7 @@ experience of updating a couple of projects that are using Spot.
 
 * Upgrading to C++14
   :PROPERTIES:
-  :CUSTOM_ID: cpp11
+  :CUSTOM_ID: cpp14
   :END:
 
   Because Spot now relies on C++14 features, programs that use Spot