Ever wondered why Tomcat reloads the context when editing web.xml?
This is a default configuration that can also be adjusted to your needs. The file conf/context.xml is the default context configuration that is used for all webapps. In this file you can find the line
which triggers the reload for any web.xml.
You can either add more resources here or, preferably, add your own context configuration with your resources.
Find out more about context configuration in the Tomcat documentation.