Added Merb.testing? method
Added Merb.testing? method

This will check for either $TESTING (as used by merb internals/plugins) or
Merb::Config[:testing], which can be set in the config options. Having an
option like this provides a nice interface for the more public facing parts of
Merb; the auto-generated spec_helper.rb file for example can just use the test
environment setting.

benburkert/merb-core,merb/merb,wycats/merb,wycats/merb,merb/merb,wycats/merb,wycats/merb,wycats/merb,merb/merb,benburkert/merb-core