extended AVMetadataCommonKeySoftware value

Added app name and version to this key to aid in debugging in
production apps.
new output setting property for capture directory

By default PBJVision writes to NSTemporaryDirectory(), but setting this
property allows the app to designate the output directory for capture.
Using [NSString stringByAppendingPathComponent:] for flexibility in
setting this property.
removed project workspace data

Added by mistake in last commit
better handling for captureDirectory property

Handles situation where user sets this property to nil.
Merge pull request #160 from blushmessenger/master

new property for specifying capture directory; extended metadata