Replace confusing quotes in exception with inspect
Add pretty_print for InstallerSet

Add always_install to #inspect as it was missing
Separate lines for readability
Add missing "then"
Use string platform for resolver specifications

When looking up specifications the resolver sets expect string
platforms.

For a local gem the parsed platform was available and used for looking
up the specification.  The specification was stored with a string
platform which meant the gem was not available (causing an exception).

Now the IndexSpecification always uses the string version of the
platform to prevent this bug.

Fixes #664
Add functional test for #664

I think the test for #664 is insufficient to prevent recurrence of the
bug.  This test uses the same operations as the resolver to help ensure
a regression does not occur.
Install files starting with '.' (Fixes #680)

The '*' pattern doesn't match files starting with '.' unless you
use File::FNM_DOTMATCH.  Some gems depend on files starting with
'.' being installed.  Excluding files starting with '.' was not
the intention of the author that added the fnmatch code.
Add #680 and #681 to History
Ignore default gems when building indexes

When default gems were added they managed to slip their way into the
index generation code as they were not explicitly included.  This meant
uninstallable gems where included in the index.

Now the default gems are filtered out of the index.

Fixes #661
Remove trailing whitespace
Set release version and date