1) download & extract the new tomcat (binary distribution)
2) remove <new-tomcat-dir>/webapps/*
3) move to new tomcat-dir:
<old-tomcat-dir>/webapps/*
<old-tomcat-dir>/.gitignore
<old-tomcat-dir>/logs/.gitignore
<old-tomcat-dir>/work/.gitignore
4) in <new-tomcat-dir>/conf/server.xml:
4a) search for the active "Connector" tag and add the following to its properties:
URIEncoding="UTF-8"
-> sets default parameter encoding to UTF-8 (required by the wiki app)
maxHttpHeaderSize="262144"
-> support redirect URLs with a lot of logged involved and failed keys
5) replace <old-tomcat-dir> with <new-tomcat-dir>
