Fix tipsy not shown for next message in trash

Fixed message deletion bug, and message loading.

JSCS for attachment.js

JSCS for folder.js

Use docker on travis .....

Fixed delete function.
Fixed message loading function.
Modified delete function to load a newer message upon deletion, otherwise load an older message upon deletion.
Fixes #730 and #753

fix reply fields overlapping message header bar

return HTTP 404 if message does not exist

JSCS for send-mail.js

client-side message cache

Open composer from an email address in message view

JSCS for attachment.js

JSCS for compose.js

Adds JSCS - and formats settings js

Format settings.js

fix codacy js issue

- first 10 messages
- additionally other 10 most recently loaded messages
partially implements #480

show OC notification when draft was saved successfully

Fix iconv issue and allow proper display of some html messages

filter deleted mails

centering the "add new email address" form

Fix undefined index - fixes #656

centering new email account form horizontally and vertical adjustments also

This is a combination of 6 commits.
centering the <new email> form

stupid error in blind css

changing the structure of the markdown arround  <new email> form for it to be included into the #app-content div, and therefor it can be centered while keeping absolute positionning, in respect with the rest of the cascading css structure of the app

CSS adaptation of the new email account form

adaptation of the css structure now that content is truly relatively positionned; removes a bit of top margin to now have scroll in the form on small heighed screens

switching to a cleaner aligning method

now adding padding to the top to 'center' the form vertically

also centering the loading.gif to the form, forgot to do so.

syntax correction based on Codacy

show ellipsis on long mail addresses