Fix for TextBoxes not moving the text in text boxes when moving the
carat or adding characters that exceed the textbox's visible space.

- Adds empty PostLayout() in TextBox class to avoid Label's PostLayout
  from being called. Otherwise the text's position will always be set to
  a fixed position defined by the alignment.

Misc changes:
- Removed extraneous semicolon in TextBox::MakeCaratVisible()
- Added newline in TextBox.cpp to avoid GNU compiler warnings
Fix for crash when exiting OpenGL samples

Cause:
- Order of operations was causing the crash. The OpenGL renderer was being
  deleted before the TexturedBase skin, which depended on it.

Fix:
- skin was changed to a pointer, allowing it to be deleted before the
  OpenGL renderer.
Added newline at end of OpenGLSample
Merge pull request #28 from DeeKayHT/TextBox_Fix

Fix for TextBoxes not moving the text when caret needs to move
Merge pull request #29 from DeeKayHT/OpenGL_Fix

OpenGLSample crash fix
Merge branch 'master' of https://github.com/garrynewman/GWEN