dot icon size choice, for gcylc and gsummary

A small diversion with big visual impact (IMHO). Task state "dot" icons are arguably too small on a large computer screen. This adds:
 *  choice of "small" (original), "medium" (new default), or "large" icon size via gcylc.rc
 * transparent instead of white holes in hollow and suite-stopped xpms
 * tweaked the "high-contrast" colour theme a bit

@benfitzpatrick - please review (this is mostly xpm template, very few lines of code changed).

![large-icons](https://f.cloud.github.com/assets/2362137/2384000/3178d5a0-a906-11e3-88d3-bedb71a954bc.png)