* [fix] stop action if trigger fails for validate and before_, fixes frappe/erpnext#10200

* [fix] stop action if trigger fails for validate and before_, fixes frappe/erpnext#10200

* [fix] codacy

* [fix] add test to tests.txt

* Replaced Python 2 print syntax with Python 3 syntax

* Update utils.py

Importing six.text_type instead of types.UnicodeType and
six.binary_type instead of types.StringType

io.FileIO is available in both Python 2 and 3, file is removed in
python 3.

* [hotfix] fixes for AttributeError: 'NoneType' object has no attribute 'split'

* [tests] added test cases for not in and in filters

* [minor] check if user exists or not

* [minor] remove the User Permission Link from module view

* [hotfix] Linked with and List item click (#3803)

* [hotfix] Linked with and List item click

* Run a single test using Test Runner

* Add test for Linked With

* [minor] List view fixes

* bumped to version 8.6.3

* [Fix] Getting an error datetime.datetime is not iterable during importing purchase invoice data (#3818)

* Update quick_entry.js (#3815)

Fix typo

* bumped to version 8.6.4

* Hide links in pdf

* Show footer in print preview

Unlike Python 2, Python 3 does not automatically unpack arguments
to lambdas passed as a tuple into named arguments.
Redefinining lamdas to accept separate arguments instead of a
tuple allows them to work in both Python 2 and 3.

StringIO and cStringIO modules are replaced with io.StringIO in
Python 3. six.StringIO is an alias for StringIO.StringIO in
Python 2 and io.StringIO in Python 3

* Email footer refactor

* styling fixes

* Unsubscribe message

* fix test

Python 3 (PEP 8) strictly disallows mixed use of tabs and spaces
for indentation
frappe innstalltion only throws error on frappe/utils/jinja.py as
of now but the rest are almost equally likely to fail, so changed
all of them in one commit

Fix typo

* [refactor] user permissions

* [fix] tests

* [ux] user-permissions

* [minor] cleanup system settings

* [minor] end progress