limit queries

limit the number of queries per ip per day, default is 3, configurable in web.xml, effective immediately (no need to restart tomcat).
files added: 
* queryexceeded.html
* SimpleQueryLimitFilter.java
files updated:
* web.xml


Can we change this and other variable names (sameDL, dlCounts, etc) to sameQ, qCounts, etc to better match the fact that we are counting queries