added ellipsis truncation to overflows to TOC entries

For indented entries in the TOC, if the chapter name is longer than the width of the TOC box, the name will wrap to the second line and be unaligned. Instead of wrapping, just truncate the chapter name using text-overflow: ellipsis.
A bit more null-safety in the Selection polling.
add gala reference to compat tests
Detect ie 11 properly

In IE 11, the user agent string was changed and attacheEvent was also
removed. This does not directly depend on the user agent string as this
has changed a bit.
Merge pull request #227 from danshultz/dev-ie-11-updates

Detect ie 11 properly
Merge pull request #226 from danshultz/fix-compat-index-ref

add gala reference to compat tests
Merge pull request #225 from ricefield/master

added ellipsis truncation to overflows to TOC entries
The slider wait graphic now implemented as CSS gradient, replacing image.