Fix broken links and redirects

Author: stevepiercy

docs/glossary.md

@@ -99,7 +99,7 @@ CloudFormation
 
 Travis CI
     Travis CI is a hosted, distributed continuous integration service used to build and test software projects hosted at GitHub.
-    Open source projects may be tested with limited runs via [travis-ci.org](https://travis-ci.org).
+    Open source projects may be tested with limited runs via [travis-ci.com](https://www.travis-ci.com).
 
 Solr
     [Solr](https://solr.apache.org/) is a popular, blazing-fast, open source enterprise search platform built on Apache Lucene.
@@ -367,7 +367,7 @@ gettext
 
 .po
     The file format used by the gettext translation system.
-    See https://www.gnu.org/software/hello/manual/gettext/PO-Files.html.
+    See https://www.gnu.org/savannah-checkouts/gnu/gettext/manual/html_node/PO-Files.html.
 
 i18ndude
     Support tool to create and update message catalogs from instrumented source code.

docs/i18n/contributing-translations.md

@@ -98,7 +98,7 @@ If you do not have commit access on GitHub [collective group](https://github.com
 
 The request will appear for `plone.app.locales` authors.
 
-If it does not get merged in a timely manner, ask on the Plone Community Forum category [Translations and i18n/l10n](https://community.plone.org/c/development/i18nl10n).
+If it does not get merged in a timely manner, ask on the Plone Community Forum category [Translations and i18n/l10n](https://community.plone.org/c/development/i18nl10n/42).
 
 
 ## Resyncing translations
@@ -113,4 +113,4 @@ To release a new `plone.app.locales` version, [read `RELEASING.rst`](https://git
 
 ## Support
 
-Please ask questions on the Plone Community Forum category [Translations and i18n/l10n](https://community.plone.org/c/development/i18nl10n).
+Please ask questions on the Plone Community Forum category [Translations and i18n/l10n](https://community.plone.org/c/development/i18nl10n/42).

docs/i18n/internationalization.md

@@ -388,7 +388,7 @@ Do not use `easy_install i18ndude`.
 `i18ndude` depends on various Zope packages, and pulling them in to your system-wide Python configuration could be dangerous, due to potential conflicts with corresponding, but different, versions of the same packages used with Plone.
 
 ```{seealso}
-https://markmail.org/message/gru5oaxdl452ekh6#query:+page:1+mid:m22a2ap4xwtwogs5+state:results
+https://markmail.org/message/ugq72cftmju4xgjh
 ```
 ````