HideBars can hide the default blizzard shapeshift, stance, stealth bars. The icons would be better off moved from the spell book manually to the action bars to take advantage of keybinds and other features.

Command:
/hidebars

Options:
/hidebars off (disable and show bars temporarily)
/hidebars on (enable) (default setting)

Install:
Move the files to the game folder, .\World of Warcraft\Interface\AddOns\HideBars\*.*