assertXpath: Check array length prior to array access

This prevents the error "Element at position [1] doesn't exist in array" if xmlSearch didn't return any results and a text for comparison was passed.
fixed unscoped variable in JavaLoader

unscoped variable in query loop causes error on Railo when strict scoping is used
Merge branch 'master' of github.com:phofmann-trust/mxunit into phofmann-trust-master
Merge branch 'phofmann-trust-master' into develop