use 'mail' instead of 'Mail' for bower to prevent warning

Enhanced keyboard event handling + new shortcuts

smoother transition when adding another account

remove obsolete folder reset event + event handler

use underscore to debounce search filters; do not re-search the same …

update/unify license headers

0.5.3 version bump

update grunt

open first mailbox when clicking the account's email address

Message Backbone model/collection

load more messages button is obsolete with infinite scroll

Update composerlock to https urls

update changelog for 0.5.2

fetch UIDs and DATEs of all messages and do the pagination client side