Support for size of gravatar image

Added support for the size (s) argument in the Gravatar API
Update modelx.py
Update modelx.py

this breaks compatibility
Update UserX, with back compatibility
Update user_list.html
Update profile.html
Merge branch 'patch-1' of github.com:xcash/gae-init
Fixed avatar for HDPI screens in user_list.html
Updated Bootstrap to 3.0.1
Update util.py
Update admin.py
Update main.py
Merge pull request #18 from topless/patch-1

Added email_filter for email form fields
Form macros are now accepting keyword arguments for stuff like autofocus, placeholder, etc
Autofocus flag is now set to the first input in forms
Simplify code - used util.uuid().
Used util.uuid() instead uuid().
Merge pull request #19 from gmist/secret_uuid

Use util.uuid() for generate flask_secret_key
Added link to GAE instances.
Open instances page in new tab.