added documentation on how to contribution to the 0.9.x branch
added build and calabash.framework to .gitignore because they should not be commited
backdoor calls made with unrecognized selectors no longer crash the
app. instead a dictionary is returned with the following key/values

outcome => FAILURE
reason => application delegate does not respond to selector X
details => an informative message with examples and prototypes

https://groups.google.com/d/msg/calabash-ios/eHpH2hh2TUQ/rIosmm7s2GcJ

tested on briar-ios-example 0.0.7
git@github.com:jmoody/briar-ios-example.git
commit 249e7a33a0f1ca16ae12ce6e03b41426acf9a68c
Merge branch '0.9-backdoor-should-handle-unrecognized-selector' of github.com:jmoody/calabash-ios-server into 0.9-backdoor-should-handle-unrecognized-selector

Conflicts:
	README.md