Added Find Owning View Controller command

Shortcut is `fovc`. Given an input `UIView` this command will walk the next
responder chain until it fines the UIViewController that owns this view.
Fix description for fovc command

Fixes comment at https://github.com/facebook/chisel/pull/13/files#r10396271
Add found view controller to pasteboard
Handle int conversion exceptions
Added object helpers for class checking.
fix bug in example defining a custom command

Example code in readme used two different names for the class defining
the example code, resulting in an error when attempting to load the new
command.

This fix just updates the code to use the same name consistently, so
that the example works.
Merge pull request #28 from algal/master

fix bug in example defining a custom command
Add upwards option to pviews command
Update README.md
Merge pull request #29 from facebook/pviews_upwards

Add upwards option to pviews command
Merge pull request #31 from dstnbrkr/master

Update README.md
Changed regex handling for commands fv/fvc. The findall method is replaced with finditer in order to support groups in regex pattern.
Moved the fovc function into the fvc function

fvc will default to searching for view controllers via class name regex. If the --view option is set, we can search for the owning view controller.
Merge pull request #13 from jkubicek/master

Added Find Owning View Controller command
Merge pull request #25 from antons/visualize

Merged show{view,layer,image,imageref} into visualize
Merge pull request #32 from nullp0inter/regex-match-fix

Changed regex handling for commands fv/fvc
Merge branch 'master' of https://github.com/facebook/chisel into develop