Consider merging spim-bead-registration pages

[hinerm]

• SPIM_Bead_Registration
• SPIM_Bead_Registration_(deprecated)

Is the deprecated page actually necessary? Is there a way to use the deprecated plugin? The pages could be merged, or unified via a plugin family top-box (as proposed in #53)

[ctrueden]

@StephanPreibisch Could you please comment on the best way to proceed with these two pages? Do you want to leave them both? Can they be combined? It's not clear to me what would be best, just from looking at each page's content...