Corrige des erreurs de syntaxe de reStructuredText suite aux warning lors de la génération.

/4.2/source/framework/import.rst:15: WARNING: Literal block expected; none found.
/4.2/source/framework/index.rst:42: WARNING: Literal block expected; none found.
/4.2/source/generateur/vue.rst:18: SEVERE: Title overline & underline mismatch.
/4.2/source/sig/geocodage.rst:20: WARNING: Literal block expected; none found.
/4.2/source/sig/layers.rst:88: WARNING: Literal block expected; none found.
/4.2/source/sig/layers.rst:193: WARNING: Literal block expected; none found.
/4.2/source/sig/mapserver.rst:42: WARNING: Inline strong start-string without end-string.
/4.2/source/sig/outils.rst:5: WARNING: duplicate label outils, other instance in /4.2/source/outils/index.rst
/4.2/source/versions/svn.rst:139: WARNING: Inline interpreted text or phrase reference start-string without end-string.