Update version and changelog.

Author: kpeeters

cmake/version.cmake

@@ -1,7 +1,7 @@
 set(CADABRA_VERSION_MAJOR 2)
 set(CADABRA_VERSION_MINOR 3)
 set(CADABRA_VERSION_PATCH 7)
-set(CADABRA_VERSION_TWEAK 4)
+set(CADABRA_VERSION_TWEAK 5)
 set(COPYRIGHT_YEARS "2001-2021")
 math(EXPR SYSTEM_BITS "${CMAKE_SIZEOF_VOID_P} * 8")
 find_program(GIT git PATHS ${GIT_DIR})

web2/cadabra2/source/changelog.html

@@ -18,6 +18,7 @@ <h1>Change log</h1>
 <a name="master"></a>
 <h3>github master (2.3.7)</h3>
 <ul>
+  <li>Option to display negative powers as fractions (Dominic).</li>
   <li>New algorithm <tt>slot_asym</tt> to (anti-)symmetrise objects in
   indices by giving index positions instead of names.</li>
   <li>New functionality to implement algorithms in Python (Dominic).</li>
@@ -39,6 +40,7 @@ <h3>github master (2.3.7)</h3>
   <li>Fix LaTeX code to avoid some global variable name clashes.</li>
 </ul>
 
+<a name="2.3.6"></a>
 <h3>2.3.6 (released 30-Dec-2020)</h3>
 <ul>
   <li>Once further change to the installation path of