Merge pull request #40 from distantcam/master

PropertyChangedEventArgs invoker method
bump version, fix some spelling
dont need pepitaget
exclude non public ischanged

fixes #50
bump version
work on issue
add change
adding support for on property changed with before after
Unoptimized onchanged call with before after (need to be smarter about invoker use of before and after)
Optimize before variable injection
track after variable
modify according to code review notes
Merge pull request #51 from DamianReeves/issue48

Add support for request in #48
bump version
make it a dev nuget
Broken test for issue #31.