Help: More syntax highlighting for literal blocks

Covers almost all blocks containing actual code, except:

* Parsed-literal blocks can't be highlighted, including many command
  summaries and substitution-heavy docs like find_... commands.
  This is a Sphinx limitation.

* Code with errors, like CMP0049, DEPLOYMENT_ADDITIONAL_FILES,
  DEPLOYMENT_REMOTE_DIRECTORY, @PACKAGE_INIT@ substitution in the
  tutorial, bracket arguments/comments in cmake-language.7 and
  cmake-developer.7.

* FindQt4 module, which needs reformatting.

Modules/CPack.cmake

@@ -176,7 +176,9 @@ installers.  The most commonly-used variables are:
 
   The name of the package file to generate, not including the
   extension.  For example, ``cmake-2.6.1-Linux-i686``.  The default value
-  is::
+  is:
+
+  .. code-block:: cmake
 
     ${CPACK_PACKAGE_NAME}-${CPACK_PACKAGE_VERSION}-${CPACK_SYSTEM_NAME}
 
@@ -197,7 +199,9 @@ installers.  The most commonly-used variables are:
   .. versionadded:: 3.7
 
   An algorithm that will be used to generate an additional file with the
-  checksum of the package.  The output file name will be::
+  checksum of the package.  The output file name will be:
+
+  .. code-block:: cmake
 
     ${CPACK_PACKAGE_FILE_NAME}.${CPACK_PACKAGE_CHECKSUM}