Enabled proxy support in Tests

Some tests need to access github.
At least for tests not running in a Jenkins instance
the proxy system properties have not been used.
Fixed test test_getAllLogEntries (behind proxy)

test_getAllLogEntries fails with:
Cloning into 'git-client-plugin'...
fatal: Unable to look up github.com (port 9418) (No such host is known. )

"git" protocol port not accessible behind firewall?
Local cleanup issues make test fail

Temporary folders sometimes cannot be deleted.
Tests should not fail due to this.
Fixing RemotingTest - delete temp failed during teardown

...on Windows (in Eclipse).