Rework fm3res.str/fm3dll.str to be java style properites file

[Steven Levine]

fm3str.str requires a custom binary to maintain it. It would be better if this file was pure text file. A java style properties file would work. The current loader would be replaced with one that loads strings on demand. This will result in a minor improvement in startup time and in memory utilization. There will be a minor increase in the time required to do the first time load of a specific mesasge.

We will need to take some care no to destroy customized version of fm3res.str. Probably renaming the file to fm3res.dat will be sufficient.