Issue #00005457

WGA.context() not isolated in isolated scripts (f. e. controllers)

In issues #00005250 and #00004849 we introduced WGA.context().

This context object should be "isolated" if the calling tmlscript method is isolated. This currently is not the case witch may lead to errors and makes it necessary to declare the method as nonIsolated().

Sample error is "request not available" in WGA.nav().

We now return an isolated version of the TMLContext object if WGA itself is isolated.