Added 2 textboxes for proxy username and password; encrypted when saved and decrypted when loaded.
Added 2 checkboxes; one for bypassing proxy for xenserver connections, one for providing proxy credentials.
Removed checkbox for bypassing proxy for local addresses.
Controls are no longer enabled/disabled when the related proxy option is selected/deselected.
Making changes to a control (e.g. username, bypass checkbox, etc) selects the 'Use this proxy server' option automatically.
Removed "Bypass proxy server for local addresses" option.
Basic and Digest authentication implemented. Tested with FreeProxy (Basic+Digest), CCProxy (Basic) and AnalogX Proxy (no authentication); each were tested with correct credentials, incorrect credentials and missing credentials; all gave expected results.
Signed-off-by: Frederico Mazzone <fredericom@citrite.net>
