issue-118: exposed statistics via jmx beans
make sure the count happen on success operations
removed jmx module, rebase
deleted jmx folder
removed getURI
unused import
fixed javadoc
add putIfAbsent and replace observers, fixed stats logic in get with cache loader
Merge pull request #132 from hhuynh/issue-118

Issue 118
excluded from findbugs
intentional code, excluded from findbugs
Merge pull request #162 from hhuynh/issue-118

Issue 118: findbugs exclusion
 #149 fix some javadoc and compiler warnings