Added a small-res fix to ToggleSwitch's position.
It corrects a rounding and conversion issue on the line-height property that causes the position of the font-symbol inside the element to not remain centered. Webkit appears to be lazily rounding to the wrong pixel in some cases which causes this offset.

Enyo-DCO-1.1-Signed-off-by: Blake Stephens <blake.stephens@lge.com>
Merge pull request #1862 from enyojs/fix-ToggleSwitch-blakestephens

Added a small-res fix to ToggleSwitch's position.

Reviewed-By: Aaron Tam (aaron.tam@lge.com)
Integrated-By: Aaron Tam (aaron.tam@lge.com)