Revert "Merge pull request #4 from mtwebster/warp"

This reverts commit 1e688e17c4aa652e8bc551f415487738e7d3a5b9, reversing
changes made to 6415e1da57d689e88768ef2413cb0a75dcde068c.
gtkrange:  Disable drag-and-hold zoom mode (still works with shift-drag),
Disable click-warps-pointer behavior for GtkScrollbars only.
Merge pull request #8 from mtwebster/gtkrange-fix

GtkRange fixes