don't profile static files

litters profile dir with useless profiles. add test to check for
this
disable in production mode unless config forces

allows deployment of app to production without having to make any
changes to config or code and will run without loading the plugin
allow passthrough of Devel::NYTProf env options

along with a test for this. see the documentation at
https://metacpan.org/pod/Devel::NYTProf#NYTPROF-ENVIRONMENT-VARIABLE
for a complete list. N.B. you can't supply start or file as these
are used internally in the plugin so will be ignored if passed
allow config of hooks to start/stop profiling

test all possible variations of pre and post hooks to check args
are correctly assigned - even if some variations aren't sensible
in the context of profiling

update Changes, bump VERSION to 0.05, update perldoc to explain
all possible config variables