ENH: Added StatisticsRelabelImageFilterTest to testing

The itkStatisticsRelabelImageFilterTest1.cxx file has been included in the
/Modules/Filtering/LabelMap/test/CMakeLists.txt so that it can actually be
tested. A fix has been applied to the file since the feature input was not
being set. The necessary test images are also being included. Compiles and
runs fine under Windows 7, Visual Studio 10.

Change-Id: I042c8620e0cc8dde395330924fe53a20b20c724b
BUG: Add support for signed char output

This patch addresses the following JIRA ticket:
https://issues.itk.org/jira/browse/SIMPLEITK-393

The types "char", "signed char" and "unsigned char" are distinct
intrinsic types. And char may be signed or unsigned. It has been
generally assumed that ImageIOBase::CHAR refers to a signed
type. To support writing of "int8_t" types, the correct typemap has
been added.

Change-Id: If4afaf277cf98d83d9a007b122631ab2aea4a647
BUG: Copy/paste error

Coverity reports:

CID 1080814 (1 of 1): Copy-paste error (COPY_PASTE_ERROR)
copy_paste_error: "it" in "it" looks like a copy-paste error. Should it say "it2" instead?

Change-Id: I40cbe342f3330b8043febb3b8ecc298189adc34e
Merge topic 'Coverity_CutPasteError'

ac523125 BUG: Copy/paste error
Merge topic 'StatisticsRelabelImageFilterCodeCoverage'

d83a3907 ENH: Added StatisticsRelabelImageFilterTest to testing
Merge topic 'OptionalSupportSignedCharImageIO'

70c8a7da BUG: Add support for signed char output
COMP: Arguments of wrong type

Double was passed for unsigned char argument.

Change-Id: I65e7efa555330562df3e5ace91c7d8a62462a5c7
Merge topic 'MeshTestWarnings'

0b40f0e5 COMP: Arguments of wrong type
BUG: Buffer not null terminated

Coverity reports:
buffer_size_warning: Calling strncpy with a maximum size argument of
32 bytes on destination array "header.filename" of size 32 bytes might
leave the destination string unterminated.

If the buffer is treated as a null terminated string in later
operations, a buffer overflow or over-read may occur.  In
itk::​BioRadImageIO::​Write(void const*): The string buffer may not
have a null terminator if the source string's length is equal to the
buffer size.

Change-Id: I3b2a5fa83b0354580a99a48907a0518e785f2a6e
Merge topic 'Coverity_BioRadImageIO'

6773f205 BUG: Buffer not null terminated