Fix incorrect val display on packed nil interfaces.

This was reported by shurcooL as issue #12.
Add tests for packed nil interfaces.

This commit adds tests for nil interfaces packed inside maps and slices to
test the recently added fix for issue #12.
Update test coverage for packed nil iface fix.

This commit updates the test coverage report in include the latest tests
for the packed nil interface issue reported in issue #12.
Detect nil slices and print them as <nil>.

This commit modifies the code to detect nil slices and display them as
<nil> (as opposed to simply empty slices).  For most instances a nil slice
can be treated the same as an empty slice, but there is a difference and
things like reflect.DeepEqual notice.  This change makes it clear whether
the type in question is a nil slice or an empty slice.
Add tests for nil slice change.

This commit adds tests for the nil slice change.
Update test coverage for nil slice change.

This commit updates the test coverage report in include the latest
tests for the nil slice change.
Add better support for dumping cgo char arrays.

This commit adds support for dumping a few cgo types like hexdump -C as
requested in issue #11.  In particular, it now handles char [#], unsigned
char [#], and uint8_t [#].
Add tests for recent cgo handling updates.

This commit adds tests for the recent cgo handling of char, unsigned char,
and uint8_t arrays.

In addition, it adds an architecture for the cgo specific testing based on
build constraints.  This was done because spew itself does not require
cgo, but in order to test its handling of the cgo types it needs to be fed
cgo data.  Rather than force all users to have a system which supports cgo
and an external compiler just to run the tests, the cgo test support must
explicitly be turned on via a build tag.
Add a script to generate test coverage report.

This commit adds a script which can be used to generate the test coverage
report.  It detects whether or not gcc is installed and adds the necessary
build tag to enable the new cgo tests when gcc is available.
Update test coverage for cgo handling updates.

This commit updates the test coverage report in include the latest
tests for the recent cgo handling updates for char, unsigned char,
and uint8_t arrays.
Moved files up