pgAdmin 4 commit: Add a simple version check mechanism to warn the user

Add a simple version check mechanism to warn the user if a new release is available.

Branch
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master

Details
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http://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=2a52462dbf2dc4f1658446aefac25c3051930de4

Modified Files
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web/config.py                                      | 10 ++++++
web/pgadmin/browser/__init__.py                    | 40 ++++++++++++++++++++--
.../browser/templates/browser/messages.html        |  2 +-
web/pgadmin/browser/templates/browser/upgrade.html |  2 ++
4 files changed, 51 insertions(+), 3 deletions(-)