set up the framework for a password change. Dont like the workflow right now. will change it next commit I think.
added logout, pw update, and profile update to a menu dropdown off of the user's name. it looks much cleaner this way, and will improve user experience for updating profile/etc
fixed bug with dropdown menu. previously clicking on menu items didn't direct to corresponding page. this works now.
 updated profile to exclude link to 'update profile' because this is now located in the header. Also updated the Profile_update page to exclude the link to update password. this is also done through the nav menu now.
changed the password update page so that when user clicks cancel, it directs them to their home page. This is closer to the actual workflow than the previous redirect which took the user to the profile update page. In the future, this might want to direct user to previous page...
Added a check to make sure the user trying to update a watch is actually the owner of the watch. Also added check to the watch update page that the owner/watch are matched appropriately in the request.
added try/excepts to views with object lookups. instead of returning Http responses, I raise the exception -- will create 403 and 404 views later. This commit is only for the page_views.py -- not views which actually update objects.