Merge branch 'issue813' into 1.7.x
Unset the used correlation id after the filter, and restore the original one

Fixes https://code.google.com/p/wro4j/issues/detail?id=824
add unit test proving that the problem is fixed
Merge branch 'issue824' into 1.7.x
reduce visibility of a method which is not required to be overriden by test
Merge branch 'issue824' into 1.7.x
properly cleanup Context for most of the unit tests
Merge branch 'issue824' into 1.7.x
cleanup context in most unit tests
Merge branch 'issue824' into 1.7.x
fix the issue with locating webjar & classpath resource containing query path in the uri
fix merge conflicts (partial)
fix compilation errors after merge conflicts