Fixing issues with symb link test failures
Fixing issues with symb link test failures

1. Collect files in a set, to avoid redundant deletions.

2. Keep symbolic filenames for report.

NOTE: these changes were conditioned for Python 2.6 and newer,
since that supports robust traversal of symbolic links.

cloudsmith-io/gcovr,kevincon/gcovr,thatguystone/gcovr,thatguystone/gcovr,kevincon/gcovr,cloudsmith-io/gcovr,thatguystone/gcovr,cloudsmith-io/gcovr,kevincon/gcovr,kevincon/gcovr,cloudsmith-io/gcovr,thatguystone/gcovr