don’t print error log when _logsErrors == NO
Merge pull request #181 from J-Jay/master

don’t print error log when _logsErrors == NO
Logs errors is now turned on by default.  It's easy to turn off, and if you're seeing errors then you should probably fix those.
Changed `isEqualTo:` (AppleScript support) to `isEqual:` (NSObject)

The method `isEqualTo:` is part of the scripting support API (for computing `NSWhoseSpecifier`s specifically), the proper selector would thus be `isEqual:`.

Reference: https://developer.apple.com/library/mac/documentation/cocoa/reference/foundation/Protocols/NSComparisonMethods_Protocol/Reference/Reference.html#//apple_ref/occ/instm/NSObject/isEqualTo:
Merge pull request #189 from regexident/patch-1

Changed `isEqualTo:` (AppleScript support) to `isEqual:` (NSObject)
Added methods that expose va_list arguments