Rename add_guide_legend and add_guide_axis to add_legend and add_axis
Merge pull request #170 from wch/rename-guide

Rename add_guide_legend and add_guide_axis to add_legend and add_axis
Use NULL defaults for internal scale functions
Make sure band is scaled
Allow two values for expand, and default to nice=F
Don't expand y min for bars
Don't pad histograms