[BUGFIX] EM: Adjust import-handling for deactivated auto-install

If automaticInstallation is turned off in extension manager settings,
dependency-checks are not done anymore (as no installation is done in
that case).

The tooltip in the "Get Extensions" list has also been adjusted:
- "Import" if automaticInstallation is turned off
- "Import and install" if automaticInstallation is turned on

Change-Id: I9d1a9105c4f76baf94d74a69d2d425a949fb8bc7
Resolves: #66302
Releases: master
Reviewed-on: http://review.typo3.org/42324


Reviewed-by: Sascha Wilking <sascha.wilking@hmmh.de>
Tested-by: Sascha Wilking <sascha.wilking@hmmh.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>