Support level 0 archives with Unix path separators.

Some archives exist in the wild that use Unix-style path separators
('/') instead of DOS-style path separators ('\'). Support these
correctly and add a regression test (thanks roytam1).
Force time zone to the London time zone.

The output from some tests is time zone dependent, meaning that tests
can fail when run outside of the time zone where they were written
(London). Set the TZ variable to force the time zone to the London
time zone for consistency (thanks Thomas Klausner).
Move vasprintf() into arch code.

Windows does not have vasprintf(), so add a wrapper implementation
for it (thanks roytam1).
Silence warning about 'saved' variable.
Set file modes to binary for testing.

On Windows, stdin and stdout are in text file mode by default.
Switch these to binary when running tests so that expected output
will be in Unix format and compare correctly to the expected output.
Don't build fuzzer in 'make check'.

The fuzz testing program is a one-off utility program, not part of
the standard build or tests. Only build it if it is explicitly
asked for with 'make fuzzer'.
Implement some lha_arch_win32 functions.

Add implementations of lha_arch_exists and lha_arch_chdir for Windows
file.
Fix up tests for running in Cygwin.
Implement lha_arch_utime for Windows.
Oops.
Fix extract tests for PMarc archives on Windows.

PMarc archives contain files with a period at the end - this gets
stripped off by Windows. The tests therefore need to check for the
filenames with the period stripped from the end on Windows.
Remove unnecessary includes.
Add spec file for building RPM packages.
Fix use of signed values in ctype macros.

(thanks Thomas Klausner)
Add parsing of Windows timestamp headers.
Set timestamps from Windows timestamp header.

When extracting on Windows, use the more precise timestamps from the
Windows timestamp header, if they are provided.
Minor style fixes for consistency.
More minor style fixes.
Add new items to .gitignore.
Bump version to 0.0.5, update NEWS.