pgAdmin 4 commit: 1) Added email id validation on the login page.

1) Added email id validation on the login page.
2) Added validation for the file manager.

Branch
------
master

Details
-------
https://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=b82e6dbdb8646de0bd35c7297f81a32dee5d1891
Author: Aditya Toshniwal <aditya(dot)toshniwal(at)enterprisedb(dot)com>

Modified Files
--------------
web/pgadmin/authenticate/internal.py | 15 +++++++----
web/pgadmin/misc/file_manager/__init__.py | 37 ++++++++++++---------------
web/pgadmin/setup/user_info.py | 10 +++-----
web/pgadmin/tools/user_management/__init__.py | 22 +++++++++++-----
web/pgadmin/utils/paths.py | 19 +++++++++++---
web/pgadmin/utils/validation_utils.py | 26 +++++++++++++++++++
6 files changed, 86 insertions(+), 43 deletions(-)