New: better icons for XcodeCapp 3
Fixed: Xcode created temporary files which were being processed.

When saving a xib, Xcode creates a temporary file with the name <filename>~.xib. The file event listener would sometimes pick this up and XcodeCapp would attempt to process it, but by the time nib2cib was launched it would be gone, generating an error.

Now .xib files whose filenames end with ~ are ignored.
Fixed: not enough space around status icon.
Updated XcodeCapp 3 help to reflect new features.