Improve the testing of tar -X and try to correctly handle some odd cases.

Improve the testing of tar -X and try to correctly handle some odd cases.
Here are some of the cases currently handled
(assuming test.tar contains a single entry "file1"):

 $ tar xf test.tar file1

Extracts file1 with no error.

 $ tar xf test.tar file1 file2

Extracts file1, error because file2 was requested but not found.

 $ tar xf test.tar file1 'file2*'

Extracts file1, error because 'file2*' pattern matched no entries.

 $ tar xf test.tar file1 file1

Extracts file1 with no error

 $ tar xf test.tar file1 'file*'

Extracts file1 with no error

 $ tar xf test.tar --exclude=file1

Does not extract file1, no error.

 $ tar xf test.tar --exclude=file1 file1

Does not extract file1, no error.

 $ tar xf test.tar --exclude=file2 file1

Extracts file1, no error.

SVN-Revision: 2229