translations update 2013-04-08

- updates for bitcoinstrings.cpp and bitcoin_en.ts
- changes help text for -rpcthreads to match -par
- fix a small glitch with -par to be "-par=<n>"
overhaul of the testnet icon (green color) and the toolbar icons

- redefined the green color
- created new toolbar icons
- updated the assets-attribution.txt

Signed-off-by: Jonas Schnelli <jonas.schnelli@include7.ch>
better quality windows .ICO icon file

- icon quality of the win icon of <256px resolutions are now much better

Signed-off-by: Jonas Schnelli <jonas.schnelli@include7.ch>
move COPYRIGHT_YEAR to clientversion.h

- this allows usage of that information also in other places (e.g. splash
  screen)
use the new COPYRIGHT_YEAR macro in bitcoin-qt.rc

- this reduces the places, where we need to change the year further
fix bitcoin-qt.rc not showing up in Qt Creator
Merge pull request #2487 from Diapolo/translations

translations update 2013-04-08
Merge remote-tracking branch 'jonasschnelli/new_icons' (#2497)

Conflicts:
	doc/assets-attribution.txt
Bitcoin-Qt: remove " - " on empty title in BitcoinGUI::message()

- don't display "Bitcoin - " when no title was supplied but just "Bitcoin"
Merge pull request #2503 from Diapolo/copyright-year

new COPYRIGHT_YEAR macro in clientversion.h
qt: don't show rpcconnect command line option in help

GUI can't connect to RPC. Showing this option in the help confuses
people, so remove it.
Add test patches for pull-tester to contrib/
Merge pull request #2514 from TheBlueMatt/master

Add test patches for pull-tester to contrib/
Use a uint256 for bnChainWork

Every block index entry currently requires a separately-allocated
CBigNum. By replacing them with uint256, it's just 32 bytes extra
in CBlockIndex itself.

This should save us a few megabytes in RAM, and less allocation
overhead.
Merge pull request #2513 from laanwj/2013_04_gui_remove_rpcconnect

qt: don't show rpcconnect command line option in help
qt: move export button to tabs

Having the export button at the top was confusing people into thinking
the entire wallet was exported.

This commit moves the export button to the address book, receiving
addresses and transaction tabs separately.
Merge pull request #2418 from sipa/uintwork

Use a uint256 for bnChainWork
Merge pull request #2515 from laanwj/2013_04_move_exportbutton

qt: move export button to tabs
Merge pull request #2492 from Diapolo/Qt_message

Bitcoin-Qt: remove " - " on empty title in BitcoinGUI::message()