When trying to switch to a container that does not exist, it now removes that ctnr from the session list
When creating a ctnr, it is added to the users session variables. When deleting it is removed, and if user is currently in that ctnr they are switched to their default.
Edited for consistency
Make ________Interface.system a required field
Eliminate now-redundant validation in clean()
Merge branch 'master' of https://github.com/OSU-Net/cyder into ctnr_logic

Conflicts:
	cyder/base/views.py
Fixed ctnr_delete_session being called before permissions checking
Fixed another merge conflict
Fixed ctnr's not being deleted from ctnr session list properly
Lists now order by ip's by integer value
Ranges, do not overlap, don't need to sort by end_str
Added magnifying glass for detail view, rather than object self str
GUI icons now react to hover
Most Detail pages no longer link to themselves in tables
Removed self redirect links from custom detail views
Info column no longer shows up in spreadsheet mode
Fixed broken view test
Fixed broken view
Merge pull request #240 from church29/Broken_View_Test

Fixed broken view test
Merge branch 'system-not-null'

Conflicts:
	cyder/cydhcp/interface/dynamic_intr/models.py