Adding pure virutal ImageReaderBase::Execute method

This follows similar design of the ImageFilterExecuteBase class used
for filters.

Change-Id: I01249c212256a40a5751e3d112b23737dccbaf64
Adding OutputPixelParameter paramter to ImageReaderBase class

The Set methods is suppose to return the class but this is implemented
in the base class so a bass class must be returned.

Change-Id: I872314b4d92e887cc7c4c7c84463215f48d762e7
STYLE: if statement is missing curly brackets.

Change-Id: Ic906360b42976c12221046613c881b1cf2b7c54f
Adding ImageFileReader support to use OutputPixelType

Change-Id: Ib6b93798da26187bb67412dd6344725da30894c8
Adding testing for OutputPixelType for image file reader

Change-Id: I9ef43d08d2e259341cafa099a005ece93bc72e80
STYLE: add white space between function declarations

Change-Id: I12382dca8c069fb620fc34b8a741bc1b8cba75b0
Adding support for OutputPixelType for ImageSeriesReader

Change-Id: Icca88b2379e0b8ca29786ea1b6b57ecdeafc636f
Adding testing for ImageSeriesReader with output pixel type parameter

Change-Id: I6aa3d833c7e7575e29d9afce74e47e521b10695d
Updated registration examples to specify pixel type for read

Change-Id: Ie7d9d1895229d7a55e65801f54f888ed9e04f708
Merge topic 'SIMPLEITK-345_AddOutputPixelTypeToImageReaders' into next

b4ec5199 Updated registration examples to specify pixel type for read
80ddb7d7 Adding testing for ImageSeriesReader with output pixel type parameter
de75e994 Adding support for OutputPixelType for ImageSeriesReader
211443fb STYLE: add white space between function declarations
9d86da28 Adding testing for OutputPixelType for image file reader
7a7732bf Adding ImageFileReader support to use OutputPixelType
c1a30558 STYLE: if statement is missing curly brackets.
a8f05350 Adding OutputPixelParameter paramter to ImageReaderBase class
1b454881 Adding pure virutal ImageReaderBase::Execute method