COMP: Fixes multiple warnings in IO methods.  Needs updated ITK
Merge pull request #143 from aylward/PDFIOWarnings

Fix a multitude of signed/unsigned and hidden virtual warnings in BaseIO classes.
STYLE: Used static cast from old / c-style cast
Merge pull request #144 from aylward/CppStaticCast

Resolve CppCheck error: old c-style cast
ENH: Import SyncRecord from Andrei State.

Note: does not compile -- will fix in later commits.

For reading InnerOptic recorded US screenshots, and their associated
timestamps and spatial transforms.
COMP: Make SyncRecord compile.
ENH: Add test for SyncRecord.
BUG: SyncRecord: Fix whitespace detection in header.
ENH: SyncRecord: Add remaining test from Andrei.
ENH: Change ITK version to match Slicer - includes MetaIO updates
Merge pull request #146 from aylward/ITKBumpForMetaIO

ENH: Change ITK version to match Slicer - includes MetaIO updates
BUG: Bump to correct ITK version.
Merge pull request #147 from aylward/ITKBumpForMetaIO

BUG: Bump to correct ITK version.
BUG: Add missing TubeTK headers to SyncRecord files.
Merge pull request #145 from thewtex/tracked-frames

Incorporate SyncRecord from Andrei.