Allows it to inherit parent size or editor specified

Avoids bug #50 — also makes more efficient

Instead of creating and destroying we just show or hide.

Don’t impose a minimum width either.

Increase specificity of grabbing child <li> tags

Affects #42 and
https://github.com/ebiwd/EBI-Framework/commit/f098ddc0a1e6478208eac7e7f1
f49494f9dd1d96#commitcomment-19644988

Improves jQuery 2 compatibilityt

Also remove the calls to measure each <li>, which was probably causing
havoc in safari. Affects #25 and #42

This reverts commit 8cdc32ce.

Also remove the calls to measure each <li>, which was probably causing
havoc in safari. Affects #25 and #42

Faster and more accurate to use inner/outer width. Also reduces number
of measurements. Affects #25 and #42

Take into account the padding on the left side of navigation area.