Added Hide for ID

Added function to allow generic hide_on argument for metaboxes.
google map field added
gmap added on example file
Save meta on attahchments
Rename map field JS for consistency
Update Gmaps to work with all the CMB hooks
Refactor + add elevation field
don't set zoom on every drag event
tweak the gmaps settings
Merge branch 'master' into emmunes
Test hide_on
Merge pull request #250 from humanmade/hide_for

Hide for
Fix regression - fields showing before initial draft/save
Bump version
Merge branch 'master' into gmap
Merge pull request #239 from humanmade/gmap

Gmap
Bugfix - show_on filter getting hooked in multiple times
Update readme
Merge branch 'master' into save-on-attachments

Conflicts:
	class.cmb-meta-box.php
revert remove space