Removed unused rigidSizing option
Removed headers rereating upon resizing

Rationale: if user wants to append custom elements (like resize icon) into
.rc-handler class after calling $('table').resizableColumns(), recreating them
will make it disappear.
Added option to synchronize handlers upon resizing

Rationale: better support for .rc-handler user CSS stylesheets. If user adds an
icon or custom background for grips, it won't get "stuck" during resizing
anymore. Controlled with "syncHandlers" option, defaults to true.
Merge pull request #18 from rr-/gh-pages

Better support for user-stylized handlers