partial support for group-like vscreens (vnext, vprev, vother, named moves)

[smemsh]

this restores some functionality from groups, that are missing from vscreens:

• ties in the vnext, vprev, and vother functions that were in the code but not linked to actual accessible commands.
• allows the windows to be moved to by name
• looks windows up by name first instead of number

Fixes #40

[smemsh]

also added man page updates from original push