As a result in non interactive mode we are not able to find an event returned by list command

Which is probably never; the feature is unused as far as I know.

The test was here for python3 user, to not import browser1.
Since the load of the exception does not need browser1 anymore (see
"Remove import of browser1 in BaseApplication"), this check is useless

And move it in the same place than before to help the diff...

"informations" is incorrect; try to use a better word, or the invariant "information".

refs #1424

Since the date are now not always imported, it does not make a lot of
sense to not import all date utils

It removes the import of SSL in console applications (SSL -> socket ->
base64 -> ...)

Actually, the condition are not widely used. Do not load the datetime
module if we don't run it.

The import process of requests is very expensive: it imports all urllib,
and a lot of stuff. It is a problem on slow hardware, for applications
not running browser2 (example: weboob-config update).

This patch has two mains parts:
 * introduces load_browser to load a browser only if needed (a lot of repository
   processing does not need a browser)
 * Do not import exceptions of requests, but use Weboob internals one

Before: 6455 open/190 modules imported
After: 3997 open/112 modules

One of the goal is to not import all modules needed by filters by
loading the page file.

In the same goal, move the import of parsers in the class definition.