Bitcoin-Qt: comment out unused parameter in addressbookpage
Bitcoin-Qt: never display own block count > estimated block count

- some users reported it as weird, that the estimated block count could be
  lower than our own nodes block number (which is indeed true and not good)
- this pull adds a new default behaviour, which displays our own block
  number as estimated block number, if own >= est. block count
- the pull raises space for nodes block counts in cPeerBlockCounts to 8 to
  be more accurate
- also removes a reduntant setNumBlocks() call in RPCConsole and moves
  initialisation of numBlocksAtStartup in ClientModel, where it belongs
Bitcoin-Qt: add a Reset button to the options dialog

- a click on "Reset Options" sets all options to the default values by
  removing all stored settings (QSettings), loading the defaults and
  saving them as the new settings
- before the reset is executed the user is presented a confirmation dialog
- special casing was needed for StartAtStartup
translations update (bitcoinstrings.cpp + bitcoin_en.ts)
Merge pull request #2141 from Diapolo/translations

translations update (bitcoinstrings.cpp + bitcoin_en.ts)
Merge pull request #1685 from Diapolo/Qt_add_options_reset

Bitcoin-Qt: add a Reset button to the options dialog
Merge pull request #2148 from Diapolo/est_block_count

Bitcoin-Qt: never display own block count > estimated block count
Merge pull request #2110 from Diapolo/addrbook

Bitcoin-Qt: comment out unused parameter in addressbookpage