- remove duplicate includes, that are already present in ui_optionsdialog.h
- change QIntValidator to not allow 0 as port-number
- re-order some function calls to match the Ui element order, for better readbility and to prepare for the addition of further IPv6 and Tor proxy options
- restat warning for the language selection is only shown, when the language was changed (not on simply activating the Ui element)
- split check for object == ui->proxyIp into seperate if-clause
- micro-optimize the code in the above mentioned if-clause
- unify used format for comments in the code
- introduce handleProxyIpValid() function, which handles UI elements and the
save button states for valid/invalid proxy IPs
- extend network options with a SOCKS version selection
- changing "Unit to show amounts in:" now also updates the unit used in the transaction fee box
- string updates
- link Apply button and OK button when enabling or disabling them
- use LookupNumeric() from netbase to verify proxy address (via an EventFilter)
- change proxy address field to QValidatedLineEdit and add visual feedback
- add a status label used for displaying a message for invalid proxy addresses
- allow usage of IPv6 address as proxy address
- added warning message when enabling / disabling SOCKS proxy
