#1687 fix for calendar feed when date format is different from YYYY-MM-DD

This fixes tasks and other modules dates not appearing in calendar feed because of the user date format different than 'YYYY-MM-DD'.

See merge request !856

Fixes #1597 and #1604 - Avoid lineitems deletion when using vtws_revise

See merge request !858

Fixing Documents not being sent as Email Attachments #1506

When sending Email and adding a CRM Document as an attachment, the Document was not sending due to missing filepath value
Fixes #1506

See merge request !847

removing CKEditor spell check which is broken

#1685 removing broken spell check in CKEditor

See merge request !852

align account register address with sign-in page

The account register mail address shown in the `README.md` is not identical to the address in the [sign-in page](https://code.vtiger.com/users/sign_in).

I believe the `community @ vtiger.com` is the correct address since the mail sent to `info @ vtiger.com` was never replied.

See merge request !853

Fixes #1688 in order to improve global search efficiency

See merge request !855

Fixes #1689 which prevented saving multipicklist fields in quick create

See merge request !857

getSelectedDefaultTaxMode #1561

Finally the obnoxious error that denied vtws_create, vtws_revise and more operations, since 4 years ago, is solved.
Now you don't have to patch it manually at every release anymore.

See merge request !848

popuptranslated #1684

this fixes a long lasting problem for popup calendars not picking translated strings for user set language

See merge request !850

minilist with 4 columns  #1589

Strangely it was already fixed by me but it wasn't in master so I changed the code in a tidier way that hopefully will be merged!

See merge request !851

fix for #1677

This merge requests fixes a problem preventing google events to sync in vtiger.

See merge request !846