Improved button text in online contribution pages

Modify button text on first and 2nd pages of online contribution forms per suggestions from HiDef folks at:
http://www.hidefweb.com/blog/ideas-improving-civicrm-usability-ux

Continue => Confirm Contribution
<< Go Back => Go Back

Buttons on both forms can now be individually themed via css by specifying a classed span, or themed by button type/
EXAMPLE:
/* Special styling for specific form buttons */
#crm-container span.crm-button_qf_Main_upload input {
font-size: 1.2em;
}