ENH: Add KWStyle pre-commit hook.

KWStyle is executed on files with additions and modifications according
to the TubeTK style specification and overwrite rules.

The superbuild KWStyle executable is used.

Configuration occurs in ./Utilities/SetupForDevelopment.sh.

The hook can temporarily be disabled with

  git config hooks.KWStyle false
Merge pull request #75 from thewtex/StyleHook

ENH: Add KWStyle pre-commit hook.