Bob first commit JAL-3032

- jalview/bin/cache.java
 propsAreReadable true for JS
 authordetails, builddetails "xxx" for JS for now
- org.apache.log4j -> jalview.javascript.log4j (minimal)
- jalview/util/MessageManager switch to org.apache.log4j

JavaScript Status:

jalview.io.FileFormatException: Failed to read data from source: CANNOT
ACCESS DATA AT URL 'http://www.jalview.org/examples/uniref50.fa'
((intermediate value).toBIS$O is not a function