Added + (NSString *)pathForShellCommand:(NSString *)command;
Added new test class NTBTask_ClassMethodsTests.
- added@property (readonly) NSString *launchPath;
- made changes to initWithLaunchPath:
  Initialises a new task. Unless launchPath begins with a "." or a "/" NTBTask will try to find the full path automatically, using the search path of the current process.