ENH: Ignore autocompletion clang helper files

The YouCompleteMe package for vim expansions
requires a file in the source tree to define
how the continous building of source files
for introspection needs to be done.

Change-Id: I221c3812e251752f43e37eafe65b160a73f18d30
COMP: Fix type casting build warning.

This patch fixes the build warning by a gcc compiler in the dashboard over
some implicit type-casting being performed in the
itk::SigmoidTransferFunctionTest. Compiles fine under Windows, Visual
Studio 2010.

Change-Id: Iec248a3683461babc9cf6a5b55c51fd533db339c
Merge topic 'YouCompleteMePluginIgnore'

54c973e7 ENH: Ignore autocompletion clang helper files
Merge topic 'SigmoidFix'

455a2918 COMP: Fix type casting build warning.